Prorated Salary Calculator

Enter property price, down payment, term and rate — get monthly payment, total interest and total payable.

Compute Ad Valorem Stamp Duty (AVD) on residential property at the latest rates.

Estimate Hong Kong salaries tax using both the progressive bands and the 15% / 16% two-tier standard rate (Year of Assessment 2024/25).

Hong Kong MPF contributions for employees, employers and self-employed persons using the statutory 5% rate with the $7,100 minimum and $30,000 maximum relevant income thresholds.

Project the future value of a principal plus regular monthly or yearly contributions at a given annual rate, with total interest earned.

Compute the compound annual growth rate from a start value, end value and number of years — useful for comparing long-term growth.

Compute total profit, ROI % and annualised return from initial cost, final value and holding period — useful for comparing investments.

Project the future purchasing power of an amount given an annual inflation rate and time horizon — and the nominal amount needed to keep up.

Convert between cost, selling price, markup % and gross margin % — handy for retail pricing and SMB profit analysis.

From fixed costs, variable cost per unit and selling price, find the units needed to cover all costs — plus break-even revenue, contribution margin, target-profit volume and margin of safety.

Convert a nominal annual rate (APR) at any compounding frequency to the effective annual yield (APY), or solve the inverse — essential for comparing credit-card, savings-account and mortgage rates.

Quickly estimate how many years to double your money at a given compound rate, or what rate is needed to double in a target period — with the exact logarithmic answer alongside.

From balance, monthly payment and APR, compute how many months until the loan is paid off, the total interest paid, and the minimum payment that just covers interest.

Given goal amount, current savings, monthly deposit and APR, see how many months it takes to hit the target.

Enter principal, annual rate and number of periods to compute the fixed annuity payment (PMT formula) — essential for retirement-income planning.

Enter the after-tax salary you want to take home and the calculator works back to the gross figure you need to offer (HK MPF and salaries-tax aware).

Enter property price, monthly rent and yearly expenses (rates, management, insurance, vacancy) to see both gross and net rental yield (%).

Enter annual dividend per share, share price, EPS and amount invested to compute dividend yield (%), payout ratio (%) and projected yearly income.

Enter a price and a tax rate to compute the gross total and tax amount, or work backwards from a tax-inclusive price to the net amount.

Enter property value and loan amount to get the LTV ratio, the required down-payment, and a live check against HKMA caps and the HKMC mortgage insurance ceilings.

Discount a future amount back to today using an annual rate, horizon and compounding frequency — get the present value, discount factor and effective annual rate.

Use the Fisher equation to strip inflation from a nominal rate and find the real return, with the common r ≈ i − π approximation alongside.

Apply the Trinity Study 4% rule: enter your retirement nest egg and a withdrawal rate to see the annual and monthly income it can support.

Enter monthly debt payments and gross monthly income to compute your DTI ratio against the standard lender bands (36% / 43% / 50%).

Enter principal, annual rate and term and apply I = P × r × t to find the interest earned or owed under simple-interest accrual (no compounding).

Enter the initial outlay, future cash flows and a discount rate to compute the project Net Present Value (NPV) — positive NPV means the project beats your required return.

Enter the upfront investment, projected yearly cash flows and a hurdle rate to solve for the discount rate that makes NPV = 0 — and see at a glance whether the project beats your required return.

Enter your portfolio annual return, the risk-free rate and the annualised standard deviation to compute the Sharpe ratio — excess return earned per unit of risk taken.

Compare your current mortgage against a new rate, net of refinance closing costs and penalties, to find how many months to break even and whether the whole loan saves or costs more over its lifetime.

From face value, coupon rate, yield-to-maturity, years to maturity and coupon frequency, compute a fixed-coupon bond's present price, premium/discount and current yield.

Compute the future value of a stream of equal payments (e.g. monthly savings or pension contributions) with end- or beginning-of-period timing.

Enter the market values of equity and debt, the cost of equity, the cost of debt and the corporate tax rate to compute the weighted-average cost of capital (WACC), capital-structure weights and after-tax cost of debt.

Enter a company's net income, preferred dividends and weighted-average common shares outstanding to compute basic EPS, with an optional dilutive-securities input for diluted EPS.

Enter a fixed amount per period and the buy price for each period to see total invested, total shares, average cost and current value — with a side-by-side comparison against putting the same money in as a lump sum at the first price.

Enter account size, per-trade risk percent and stop-loss distance to compute the share/lot quantity that caps your loss at the chosen risk.

Enter several debts (balance, APR, minimum payment) and your monthly extra budget; the tool runs the classic "smallest balance first" snowball method, estimating each debt's payoff month, total interest paid and total months to debt-free.

Enter an initial investment, level annual cash inflow, discount rate and horizon to instantly see the simple payback period, the discounted payback period and the terminal Net Present Value (NPV), plus a year-by-year cumulative cash-flow table — built for capital-budgeting, small-business investments, solar installs and equipment purchase decisions.

Enter your current salary, raise percentage or dollar amount and instantly see your new salary plus annual, monthly, weekly and hourly differences — handy for comparing offers, negotiating reviews and gauging inflation-adjusted raises.

Enter a target amount (FV), expected annual return and term — the tool back-solves the periodic payment you need to reach that target, the classic "how much to save monthly to hit $X by year Y" question.

Enter the level periodic cash flow C and the discount rate r — the tool returns the perpetuity present value PV = C / r and, optionally, the growing-perpetuity Gordon value PV = C / (r − g) used for consols, preferred shares and dividend-discount models.

Enter the loan amount, the number of discount points bought and the rate reduction per point — the tool returns the upfront cost, the monthly payment saving and the break-even month so you can decide whether paying points is worth it.

Enter net operating income (NOI) and total annual debt service (principal + interest); the tool reports the debt service coverage ratio DSCR = NOI / debt service — the headline risk metric banks use when underwriting commercial property loans, business loans and investment-property mortgages.

Enter a share price and EPS — the tool returns the price-to-earnings ratio P/E, the earnings yield (EPS ÷ price), and the PEG ratio (if a growth rate is supplied), then puts the result in context with typical industry bands.

Enter total liabilities and shareholders' equity to get the D/E ratio, equity multiplier and debt-to-assets ratio, with industry context (utilities, tech, banking) to flag whether the firm's capital structure is conservative or aggressive.

Enter next year's dividend D₁, the required return r and the perpetual growth rate g; the Gordon dividend-discount model returns the intrinsic price P = D₁ / (r − g) and the growth rate implied by today's market price.

Enter net income, revenue, assets and equity; the tool applies the 3-factor DuPont identity to decompose ROE = Net Margin × Asset Turnover × Equity Multiplier, so you can see whether high returns come from profitability, efficiency or leverage.

Enter current assets (cash, receivables, inventory) and current liabilities (short-term debt, payables) to get the current ratio = CA ÷ CL, with industry-standard thresholds (< 1 warning, 1–2 healthy, > 3 idle cash) to flag short-term solvency at a glance.

Enter cash, marketable securities, receivables and current liabilities; the tool returns the quick ratio = (CA − inventory − prepaid expenses) ÷ CL, a stricter view of liquidity than the current ratio because it excludes inventory and prepayments that may not convert to cash quickly.

Enter net income and shareholders' equity (beginning / ending / average); the tool returns ROE = net income ÷ equity with the conventional bands (< 5% weak, 10–15% healthy, > 20% excellent), so you can read management's efficiency at deploying equity capital at a glance.

Enter share price and book value per share (or total equity + shares outstanding); the tool returns P/B = price ÷ book value and benchmarks it against typical banks, insurers, real estate and SaaS bands — a core value-investing screen used since Benjamin Graham.

Enter annual demand D, ordering cost per order S and holding cost per unit per year H; the tool applies the Wilson formula Q* = √(2DS / H) to return the optimal order quantity, order frequency and total inventory cost — the classic recipe for stock-keeping and supply-chain planning.

Enter operating income (EBIT) and total revenue; the tool returns the operating margin = EBIT ÷ revenue, then benchmarks the result against software, branded consumer, manufacturing, retail and airline norms — the cleanest single read on core operating efficiency.

Enter the risk-free rate Rf, expected market return Rm and the stock's beta β; the CAPM formula r = Rf + β·(Rm − Rf) returns the required rate of return (cost of equity) and breaks out the equity risk premium component (ERP × β).

Enter annual cost of goods sold (COGS) and average inventory; the tool returns the inventory turnover ratio (Turnover = COGS ÷ Avg Inventory) and days inventory outstanding (DIO = 365 ÷ Turnover) — the standard lens for retail, manufacturing and e-commerce to gauge stocking efficiency and working-capital tie-up.

Enter a series of periodic returns and a target return (often 0 or the risk-free rate); the tool returns the Sortino ratio = (R̄ − T) ÷ DD, where DD is downside deviation — a risk-adjusted return measure that captures only "bad" volatility (often preferred over the Sharpe ratio) — and annualises it based on the chosen frequency.

Enter portfolio return, risk-free rate and beta; the tool returns the Treynor ratio = (Rp − Rf) / β — excess return per unit of market (systematic) risk. It is the β-based analogue of the Sharpe ratio and is favoured for evaluating diversified portfolios and fund managers.

Enter days inventory outstanding (DIO), days sales outstanding (DSO) and days payable outstanding (DPO); the tool returns the cash conversion cycle — the number of days between paying suppliers and collecting from customers, a key measure of working-capital efficiency.

Enter the P/E ratio and the expected annual EPS growth rate (%); the tool returns the PEG ratio = P/E ÷ growth, popularised by Peter Lynch — a more honest valuation read for growth stocks than the P/E alone.

Enter EBIT and interest expense; the tool returns the interest-coverage ratio (also called Times Interest Earned) — a core credit metric used by rating agencies and lenders to judge a firm's ability to service its debt.

Enter your entry price, target and stop-loss; the tool returns the reward-to-risk ratio and the minimum win-rate required to break even — the headline check every trader runs before sizing a position.

Paste a price or NAV series and the tool returns the maximum drawdown (MDD), peak, trough, drawdown duration and recovery time — the benchmark downside-risk metric for any strategy.

Enter the optimistic (O), most-likely (M) and pessimistic (P) estimates; the tool applies the PERT beta-distribution formulas E = (O + 4M + P)/6 and σ = (P − O)/6, and reports the 1σ / 2σ / 3σ confidence ranges for project duration or cost.

Enter face value, coupon rate, years to maturity and current market price; the tool bisects for the bond's yield to maturity (YTM), current yield and total coupon cash flows — the discount-rate benchmark used in bond pricing, credit-spread analysis and retirement-portfolio planning.

Enter net operating income (NOI) and property value to get the capitalization rate (NOI ÷ value). The tool also solves in reverse — give it any two of {cap rate, NOI, value} and it derives the third — the standard yardstick real-estate investors use to compare property yields.

Enter face value, coupon rate, term, payment frequency and yield-to-maturity; the tool returns the Macaulay duration (the cash-flow-weighted average years to maturity) and modified duration (the % price drop for a 1 % rise in yield) — the standard measures of a bond's interest-rate risk.

Enter gross monthly income, existing monthly debt, mortgage rate and term; the tool applies the lending-industry 28 / 36 rule to estimate the maximum PITI you can afford and the corresponding home price — a universal pre-shopping affordability screen.

Enter current salary or pension, the year-over-year change in CPI and the COLA formula to apply; the tool returns the inflation-adjusted new amount and real purchasing power — used for contract renewals, pension uplifts and year-on-year comparisons.

Enter the standard deviation of daily, weekly or monthly returns; the tool applies the √N rule σ_annual = σ_period × √N to give the annualised volatility — the standard preprocessing step for Sharpe ratio, option pricing and risk reports.

Enter two price–quantity pairs; the tool applies the midpoint (arc) formula Ed = (ΔQ ⁄ Q̄) ⁄ (ΔP ⁄ P̄) and classifies demand as elastic, unit-elastic or inelastic — a staple of microeconomics, pricing decisions and tax-incidence analysis.

Paste a series of values (prices, sales or any time-series) and a window length N; the tool returns the simple moving average point-by-point via SMA_t = (x_{t−N+1} + … + x_t) ⁄ N — staple of technical analysis, demand smoothing and KPI dashboards.

Enter a tax-exempt bond yield (e.g. US municipal bonds) and your marginal tax rate; the tool applies TEY = tax-free yield ⁄ (1 − tax rate) to give the equivalent pre-tax yield a taxable bond must offer to match it — the standard yardstick for comparing investments with different tax treatments.

Paste a list of incomes / wealth / sales values; the tool computes the Gini coefficient via G = Σ|xᵢ − xⱼ| / (2 n² · mean) (0 = perfect equality, 1 = total inequality) and reports the Lorenz curve and cumulative distribution — used in economics, sociology and sales-concentration analysis.

Enter after-tax monthly income; the tool applies the 50/30/20 rule (Elizabeth Warren) and splits it into needs (50%), wants (30%) and savings/debt repayment (20%) — the most widely taught starter budget framework in personal finance.

Enter your essential monthly expenses and target coverage (3, 6 or 12 months); the tool returns the total emergency fund target, the gap from your current balance and the months needed to reach the target at your monthly savings rate — a cornerstone of personal-finance and FIRE planning.

Enter face value, coupon rate, yield to maturity, years to maturity and coupon frequency; the tool returns bond convexity, modified duration and a second-order price-change estimate for an interest-rate move — the standard tool for fixed-income portfolio risk management.

Enter your annual spending and safe withdrawal rate (default 4%); the tool returns the portfolio size needed for financial independence via FIRE = annual spending ÷ SWR, plus Lean / Coast / Fat FIRE benchmarks — the core tool for the FIRE movement and any long-term retirement plan.

Enter the split or reverse-split ratio (e.g. 4-for-1, 1-for-10), original share count and share price; the tool returns the post-split share count, adjusted price and total market value (unchanged) — works for backtesting historical prices and is the standard adjustment in equity research and ETF tracking.

Enter the first cash flow, growth rate g, discount rate r and number of periods n; the tool returns PV = C × [1 − ((1+g) ⁄ (1+r))ⁿ] ⁄ (r − g). Used to value salary packages with annual raises, commercial real-estate leases with rent escalators, and inflation-adjusted retirement withdrawals.

Enter a cash-flow stream (negatives for outflows, positives for inflows), a reinvestment rate and a finance rate; the tool returns MIRR = (FV of positive flows ⁄ |PV of negative flows|)^(1 ⁄ n) − 1. MIRR fixes IRR's flawed implicit-reinvestment assumption and is the standard ranking metric in Excel's MIRR() function, Brealey-Myers-Allen and the CFA curriculum.

Enter the initial outlay, the future cash-flow stream and a discount rate; the tool returns PI = PV of future cash flows ⁄ |Initial Investment|. The standard ranking metric under capital rationing — PI > 1 means the project creates value, equivalent in sign to NPV but expressed as "PV created per dollar invested".

Enter the portfolio's annualised excess return over a benchmark and the tracking error; the tool returns IR = (Rₚ − R_b) / σ(Rₚ − R_b). The Information Ratio is the standard active-management performance metric, complementing the Sharpe Ratio.

Enter the bond face value, coupon rate, payment frequency, call price, years to call and current price; the tool numerically solves PV = Σ coupon ⁄ (1+y/m)ᵏ + Call ⁄ (1+y/m)ⁿ for YTC — the holding-period yield assuming the issuer calls the bond at the earliest call date.

Enter ARPU, gross margin, average customer lifespan and customer acquisition cost; the tool returns LTV = ARPU × margin × lifespan and the LTV / CAC ratio (industry benchmark 3×). Essential unit-economics math for SaaS, subscription and e-commerce businesses.

Enter the current cash balance, monthly operating expenses and monthly revenue; the tool returns net burn (expenses − revenue), gross burn (expenses) and runway in months (cash ÷ net burn) — the standard "when do we run out of money?" calculation for startups and VCs.

Enter total ad spend, impressions, clicks and conversions; the tool returns CPM (cost per mille), CPC (cost per click), CPA (cost per acquisition) plus CTR and CVR. Foundational metrics for digital advertising — Google Ads, Meta Ads, TikTok Ads — and any media-buying budget exercise.

Enter the start-of-period customer count, end-of-period count and new customers acquired; the tool returns the churn rate, retention rate and expected average customer lifetime (1 ⁄ churn). The two most-watched health metrics for SaaS, subscription and membership businesses.

Enter the asset cost, salvage value and useful life; the tool returns annual depreciation (cost − salvage) ÷ life, plus the accumulated depreciation and end-of-year book value for every year of the schedule. The most-used depreciation method in corporate accounting, fixed-asset registers and tax filings.

Enter odds in any one format and the tool returns the other three: European decimal (2.50), American (+150 / −200), British fractional (3 / 2) and the implied probability (40%). Essential conversion for sports betting, poker, value-betting and arbitrage analysis.

Enter the pre-money valuation, round size, new option-pool top-up % and your pre-round founder stake; the tool applies the standard VC pre-money pool convention to return post-money valuation, new-investor ownership, existing-shareholder share, the founder's post-round stake and the dual dilution (investor + pool). The cap-table sanity check for founders negotiating a term sheet.

Enter the project NPV (or initial cost), discount rate and life in years; the tool returns the Equivalent Annual Cost via EAC = NPV × r ⁄ (1 − (1 + r)⁻ⁿ), the annuity factor, the nominal total payments and the discount-free flat average for comparison. The standard capital-budgeting tool for comparing projects of different lifespans (e.g. a 5-year vs 8-year machine).

Enter dividends per share (DPS) and earnings per share (EPS) — or total dividends paid and net income — and the tool returns the payout ratio plus its complement, the retention ratio. The standard metric for gauging dividend sustainability and benchmarking blue-chip vs growth stocks.

Enter share price and revenue per share — or market cap and annual revenue — and the tool returns the P/S ratio with an industry-benchmarked band. The go-to valuation metric for high-growth or pre-profit companies (SaaS, biotech) where P/E breaks down.

Enter accounts receivable, credit sales for the period and the number of days; the tool returns DSO = (AR ⁄ Credit Sales) × Days — the canonical metric for how quickly a company converts customer credit into cash. Core gauge of working-capital efficiency and liquidity.

Enter the loan principal and gross annual income; the tool returns LTI = Loan ÷ Gross Annual Income and benchmarks it against common regulatory caps (UK PRA 4.5×, Irish Central Bank 4×, equivalent HKMA stress-test DSR bands). The standard screen for mortgage affordability and leverage risk.

Enter operating cash flow, capital expenditure and (optionally) the change in working capital; the tool returns Free Cash Flow = OCF − CapEx ± ΔWC and the FCF margin — the core input for DCF valuation, cash-on-cash return and margin-of-safety analysis.

A basis point (bp) is the standard unit for small changes in financial rates — 1 bp = 0.01 %, 100 bp = 1 %. Enter bps or % and the tool converts both ways, with optional application to a notional principal, rate or bond spread — eliminates the ambiguity behind "Fed hikes 25 bps" headlines.

Enter the asset cost, salvage value and useful life; the tool builds a year-by-year double-declining balance (DDB) schedule with depreciation expense, accumulated depreciation and book value — an accelerated method permitted by US GAAP and IFRS, widely used for vehicles, computers and machinery whose value drops sharply in the early years.

Enter a currency pair, lot size, quote price and account currency; the tool returns the cash value of one pip (and one pipette) for that trade — essential for MT4 / MT5 traders, forex risk management and stop-loss / take-profit placement.

Continuous compounding is the limit of more-frequent periodic compounding: A = P·e^(rt). Enter principal, rate and time; the tool returns the final amount and total interest, and contrasts it with finite-period compounding (monthly / quarterly / semi-annual / annual) — used in options pricing, Black-Scholes and academic finance.

Current yield = annual coupon ÷ current market price — the simplest measure of a bond's instant cash return. Enter par value, coupon rate (or coupon $) and market price; the tool returns current yield and contrasts it with the coupon rate — a quick first look at bonds trading at premiums or discounts.

Enter spot price, strike, time to expiry, risk-free rate, volatility and optional dividend yield; the tool applies the Black-Scholes-Merton 1973 model to return the European call and put prices, d₁ / d₂ and the full set of Greeks (Delta, Gamma, Vega, Theta, Rho) — the standard reference for option pricing, sanity-checking quotes and exploring implied volatility.

Enter cumulative sales and 1–5 tiered commission rates (e.g. 5 % on the first 100 k, 6 % on the next, 8 % above) and the tool returns total commission, marginal and effective rates, plus the contribution of each tier — used by sales reps, sales managers and year-end payroll.

Enter average order value, purchase frequency, gross margin, churn (or expected lifetime) and discount rate; the tool applies the steady-state formula CLV = (AOV × Freq × Margin) / (Churn + Discount) to give the net present value of one customer over their entire relationship — the standard SaaS, subscription, retail and e-commerce metric.

Paste the high, low and close for the last N bars; the tool applies Wilder's True Range max(H − L, |H − C_prev|, |L − C_prev|) and his RMA smoothing to give ATR — the standard volatility measure for sizing futures, FX and crypto stops and positions.

Enter starting shares, share price, annual dividend yield (DPS / price), expected annual price growth and horizon; the tool runs the year-by-year compounding loop — each dividend is fully reinvested into new shares, which earn the next round of dividends — and reports the final share count, market value, cumulative dividends and annualised CAGR. The standard analysis tool for long-term dividend reinvestment in stocks such as SPY, AAPL and KO.

Enter buy price, sell price, total cash received during the holding period (dividends / coupons / distributions) and the length of the period; the tool computes the holding-period return (HPR) and the annualised HPR — works for stocks, bonds, ETFs and funds and shows the complete picture of capital gain plus cash distributions.

Enter assets (cash, investments, property, vehicles, other) and liabilities (mortgage, credit cards, student loans, car loans, other); the tool returns total assets, total liabilities and net worth, plus the debt-to-asset ratio (DTA) and liquid-to-debt ratio commonly used to gauge financial health.

Enter the annual pre-tax cash flow from a property or investment and the actual cash you invested (down payment plus closing costs); the tool returns CoC = annual_cash_flow ⁄ total_cash_invested — real-estate investors' standard benchmark for cash-on-cash efficiency.

Enter the car price, down payment, annual interest rate and loan term; the tool applies the standard amortization formula to give the monthly payment, total interest, total repayment, and a 12-month principal/interest split.

Enter the average daily demand, demand standard deviation, lead time and target service level; the tool applies Safety Stock = Z × σ_d × √L and ROP = d̄ × L + SS to give the reorder point that meets your stock-out tolerance.

Enter the cap cost, residual value, term, money factor and down payment; the tool applies the industry-standard lease formula to split the monthly bill into depreciation, finance charge and pre-tax total.

Enter the loan principal, annual rate, scheduled monthly payment and the extra you can pay each month; the tool runs month-by-month amortisation to show the time and interest saved, and compares the with- vs without-extra payoff timelines.

Enter two assets' weights, standard deviations and correlation ρ; the tool applies σ²p = w₁²σ₁² + w₂²σ₂² + 2w₁w₂σ₁σ₂ρ to give portfolio variance / std-dev, covariance, diversification benefit and the minimum-variance weights — the heart of Markowitz modern portfolio theory.

Enter loan principal, annual rate, interest-only period and the following amortizing period; the tool gives the interest-only monthly payment, the amortizing monthly payment that kicks in afterwards, total interest paid and the cost gap vs a fully-amortizing loan — useful for mortgage shopping and personal-finance planning.

Enter the spot rate, the quote-currency (domestic) and base-currency (foreign) annual interest rates, and the contract days; the tool applies covered interest rate parity F = S × (1 + r_d × t/basis) / (1 + r_f × t/basis) to give the theoretical forward rate, forward points and annualised premium / discount — essential for FX-forward pricing, carry-trade analysis and cross-border settlement.

Enter principal, rate, amortising term and actual loan term; the tool calculates the monthly payment using the longer amortisation schedule and the balloon (lump-sum) due at loan maturity, plus total interest and a comparison vs a fully-amortising loan of the same term.

Enter equity market cap, total debt, cash, minority interest and preferred stock, plus trailing-12-month EBITDA; the tool returns Enterprise Value, the EV / EBITDA multiple and an industry benchmark band — the cornerstone multiple in M&A, private-equity and value-investing valuation.

Enter a bond's coupon rate, yield to maturity, remaining years and coupon frequency; the tool returns Macaulay duration, modified duration D* = D_M / (1 + y/k), convexity, DV01 and the approximate price change for ±1% yield moves — the standard interest-rate-risk metric for fixed-income portfolios.

Enter Planned Value (PV), Actual Cost (AC), Earned Value (EV) and Budget at Completion (BAC); the tool instantly returns the PMI / PMBOK-standard Cost Performance Index (CPI), Schedule Performance Index (SPI), Cost / Schedule Variance (CV / SV), Estimate at Completion (EAC), Estimate to Complete (ETC), Variance at Completion (VAC) and To-Complete Performance Index (TCPI) — the core indicators a PMP / PRINCE2 project manager uses to track project health.

Enter property price, down payment, mortgage rate, expected property appreciation, current rent, rent growth, alternative investment return and intended holding period; the tool computes the NPV of renting vs buying and identifies the break-even year — a universal framework without country-specific tax handling.

Enter earnings per share (EPS) and book value per share (BVPS); the tool applies Benjamin Graham's classic formula √(22.5 × EPS × BVPS) to estimate the theoretical fair-value ceiling for a defensive stock pick — the entry-level screen used by value investors and equivalent to the combined P/E ≤ 15 and P/B ≤ 1.5 Graham criteria.

Enter the nominal annual rate (APR) and the number of compounding periods per year n; the tool returns EAR = (1 + APR/n)ⁿ − 1 (the same as US APY), the apples-to-apples annualised rate used to compare credit cards, CDs, loans and bonds. Continuous compounding uses e^APR − 1.

Enter the nominal rate (or return) and the inflation rate; the tool applies the Fisher equation r_real = (1 + r_nom) / (1 + π) − 1 and contrasts it with the common approximation r_real ≈ r_nom − π — the standard way to compare investment returns, deposit rates, mortgages and pay rises against inflation.

Enter the tax-inclusive total and the tax rate (GST / VAT / sales tax); the tool extracts the pre-tax amount net = gross / (1 + rate), the tax tax = gross − net and the effective rate — the everyday tool for receipts, expense claims, cross-border shopping and bookkeeping.

Enter EPS and stock price (or the P/E ratio directly); the tool applies Earnings Yield = EPS / Price = 1 / (P/E) for the percentage earnings yield and compares against the 10-year Treasury yield to surface the *Fed-model* equity risk premium — a quick yardstick for stock-vs-bond valuation and long-horizon asset allocation.

Enter levered β_L (or unlevered β_U), the debt-to-equity ratio D/E and the tax rate t; the tool applies the Hamada equation β_L = β_U · [1 + (1−t)·D/E] to convert in either direction — the standard step in corporate valuation, WACC and CAPM analysis for *unlevering* comparable-firm betas and *relevering* them to the target firm's capital structure.

Enter your share lots (quantity + price each); the tool applies the weighted-average formula Σ(qᵢ · pᵢ) / Σqᵢ to return the average cost basis, total invested, total shares held, and the unrealised P&L (absolute and percentage) at the current market price — the most basic tool for retail investors averaging down, dollar-cost-averaging or planning an exit.

Enter par value, coupon rate, last coupon date, settlement date and coupon frequency; the tool applies either the 30/360 or Actual/Actual day-count convention to return the interest accrued from the last coupon to the settlement date (the dirty − clean price spread) — a core tool for secondary-market trading, price-quote conversion and bond accounting.

Enter outstanding balance and credit limit; the tool returns the utilisation ratio and flags the credit-score impact band (< 10 % excellent, 10–30 % healthy, 30–50 % marginal, > 50 % damaging) — the standard health check before any loan or mortgage application.

Enter an annual rate of return; the tool uses the Rule of 114, t ≈ 114 / r, to estimate the years for an investment to triple — the companion to the better-known Rule of 72 (doubling) and a quick mental-maths tool for retirement and long-term compounding planning.

Enter your target take-home income, the share of hours that are billable, annual business expenses and your tax rate; the tool back-solves the hourly rate you must charge to cover everything and still hit the target — essential pricing tool for freelancers, designers, developers, coaches and consultants.

Some older or sub-prime loans use the Rule of 78 (sum-of-digits) to allocate total interest by month in *reverse* order — meaning early payments are heavily interest-loaded and early payoff barely saves any interest. Enter principal, APR and term in months; the tool tabulates per-month interest/principal split and quantifies the front-loaded interest penalty vs straight-line allocation.

Enter the site area, allowable floor area ratio (FAR / plot ratio) and site coverage cap; the tool returns the maximum gross floor area (GFA), the per-floor footprint cap and the implied number of storeys — the standard pre-feasibility tool for property developers, investors and self-build owners.

Enter principal, annual rate and term; the tool applies the continuous compounding formula A = P · e^(rt) to return the future value, total interest, equivalent effective annual rate (EAR = e^r − 1) and growth multiplier — the standard model behind option pricing (Black-Scholes), academic finance and the theoretical upper bound of compound growth.

Compare a standard monthly mortgage with a biweekly accelerated plan (half a monthly payment every two weeks = 26 half-payments = 13 monthly equivalents per year); the tool reports total interest saved, months shaved off the term, and the new payoff date — the calculator banks use to pitch their biweekly programs.

Apply the industry-standard DIME method (Debt + Income × years to replace + Mortgage balance + Education funding) to estimate the life-insurance coverage your household needs — a universal rule-of-thumb that is more accurate than the simplistic "10× annual salary" heuristic.

Enter a small daily expense (coffee, soda, takeaway lunch, etc.), how often, and an expected investment return; the tool shows the cumulative amount over 10 / 20 / 30 years if that money were *invested instead* — David Bach's "Latte Factor" framing that makes it concrete how much your daily $5 habit actually costs at retirement.

Enter the price-ratio change k since entering a Uniswap V2-style liquidity pool; the tool returns impermanent loss IL = 2√k ÷ (1 + k) − 1 (loss vs HODL, in %) — the standard risk-quantification tool for DeFi liquidity providers and AMM yield farmers.

Enter target retirement age, target FIRE nest egg and expected real return; the tool uses PV = FV / (1 + r)^n to return your **Coast FIRE number** — how much you need to have saved today so that, with zero further contributions, compounding alone reaches the target by retirement.

Enter your loss percentage (e.g. −25 %); the tool returns the gain required to break even — gain = L /(1 − L). A 25 % loss needs a 33 % gain to recover; a 50 % loss needs 100 %. The result is shown alongside a 10–90 % loss table so you can see how recovery requirements explode with deeper drawdowns.

Enter your purchase price, initial margin and maintenance margin, and the tool returns the stock price at which a broker margin call is triggered — P_call = P_buy × (1 − IM) / (1 − MM). Works for any long-equity margin account.

Enter the system cost (after rebates), daily kWh production, and your current electricity rate; the tool returns annual savings, simple payback years, 25-year lifetime savings and simple ROI — useful for residential and commercial solar PV investment decisions.

Enter your initial investment, gross annual return, fund expense ratio (MER / TER, % p.a.) and time horizon; the tool compares the with-fees and zero-fee final values, the total fees paid and the annualized return drag — quantifying why low-cost ETFs and index funds matter for long-horizon investors.

Enter your cash balance, monthly burn rate and an optional monthly burn-growth rate; the tool returns runway in months and the projected zero-cash date — a staple metric for startups, sabbaticals and career-break planning.

Enter the current values and target percentages of 2–4 assets; the tool returns the buy / sell amount needed to bring each back to its target allocation, with an optional *cash-injection (no-sell) mode* to avoid taxable disposals — useful for 60/40 stock-bond, three-fund and FIRE allocations.

Enter loan amount, annual rate and term to generate a full month-by-month split of principal vs. interest plus remaining balance, with annual subtotals.

Enter your card balance, APR and minimum-payment rule (percent of balance or fixed floor) to see how many months / years it would take to clear and how much total interest you pay — the answer is usually alarming.

Seen "$560 after 30 % off" and need the original price? Enter the sale price and discount percentage to back-solve the original price, the amount saved and the share you actually paid — handy for online-shopping comparison, refunds and bookkeeping.

Inspired by Your Money or Your Life — subtract commute time, work meals, work clothes, child-care and other job-only costs from your gross pay to see your real take-home per hour of life spent. The result is often 30–50 % lower than your nominal hourly rate.

Enter your monthly take-home pay and how much of it you save; read the savings rate percentage instantly. Using the standard 4% safe-withdrawal framework, the tool estimates how many years to financial independence (FI) if you keep spending at your current level.

Enter your gross income and the total tax you actually paid; read the effective tax rate as a percentage and compare it to your marginal bracket. Also shows net take-home, average tax per month and how many of your working days went to taxes.

Enter your current remaining principal, rate, remaining term and the lump-sum prepayment; using the original rate and remaining term, the tool re-amortises the loan and shows the new monthly payment and total interest savings.

Using the universal "30 % gross-income rule" and landlords' "40× annual rent" qualifier, enter your gross monthly income to see recommended max rent and the max rent a landlord will typically approve.

Enter taxable income and your jurisdiction's progressive tax brackets (up to 7 tiers); the tool returns total tax, marginal rate (top bracket touched) and effective rate (total tax ÷ income) — works for any country's progressive tax system.

Enter headcount, average hourly rate (or monthly salary equivalent) and meeting length; the tool returns how much the meeting actually costs and a per-minute burn-rate to help decide whether to extend by another 30 minutes.

Enter take-home income, savings rate, expected real return and safe withdrawal rate (SWR). Uses Mr. Money Mustache's "Shockingly Simple Math" formula to return years to financial independence (FI) and the target portfolio size.

Enter two quotes against USD (or a shared base) — instantly returns the X/Y and Y/X cross rate, with optional bid/ask spread.

Enter your down-payment goal, current savings, monthly contribution and savings APR to find the months, years and target date — along with the total you contributed and the interest earned.

Enter monthly rent and the move-in or move-out date to compute partial-month rent owed, prorated by days occupied — useful when taking possession mid-month or leaving before month-end.

Enter your points / miles balance, the cents-per-point redemption rate and any redemption fee to see the net cash value and your effective conversion rate.

Enter total trip budget, number of days, and the percentage split between lodging / food / transport / activities to get a daily cap and per-category daily amounts.

Enter your donation amount and marginal tax rate to find the tax saved and the real net cost of giving.

Enter an annual rate to estimate the time it takes to double an investment under continuous compounding via 69 ÷ r, alongside the exact ln 2 ÷ r benchmark and a comparison to the Rule of 72.

Enter your annual (or monthly) salary and see ring budget ranges using the classic 1-, 2- and 3-month salary rules, plus a custom-percentage option.

Enter sale price, loan amount and a typical regional percentage to estimate total closing costs — lawyer, title insurance, appraisal, taxes, recording and miscellaneous.

Enter transaction amount, processing percentage (e.g. 2.9 %) and per-transaction fixed fee (e.g. $0.30) to get merchant fee and net receivable; gross-up mode also solves "to net X, what do I charge?"

List each recipe ingredient with its purchase amount, purchase price and amount used in the recipe — get each ingredient's actual cost, the total recipe cost and the cost per serving for menu pricing or household budgeting.

Enter revenue and net income to instantly compute the net profit margin % — the core profitability ratio measuring how much net profit a business keeps from every dollar of sales.

Enter working capital, retained earnings, EBIT, market equity and sales (as % of total assets) — get the Altman 1968 Z-Score and the bankruptcy risk zone (safe / grey / distress).

Enter annual revenue and beginning / ending total assets — instantly compute the asset turnover ratio (Revenue / Average Total Assets) measuring how efficiently a firm uses its assets to generate sales.

Enter average inventory and annual COGS — instantly compute the average number of days inventory sits before being sold (365 × Inventory / COGS), a key inventory efficiency metric.

List each debt (balance, APR, minimum payment) plus the extra monthly cash you can throw at the plan, then watch the *avalanche* method (highest-APR debt first) project each payoff month, total interest and total months to debt-free.

Enter the start value, cash flow and end value for each sub-period to strip out deposit / withdrawal timing — TWR reports the geometric-mean return that measures pure manager performance.

Combine purchase price, annual running cost, annual maintenance, useful life and resale value to get total cost of ownership and amortised cost-per-year — the apples-to-apples way to compare a cheap vs expensive option.

Enter current assets and current liabilities; the tool returns working capital (= CA − CL), the working-capital ratio (current ratio = CA / CL) and a short-term-liquidity verdict — daily tool for SMB owners, accountants and credit analysts.

Enter the early-payment discount rate, the discount window and the net credit period; the tool returns the annualised cost (APR and EAR) of *not* taking the discount — the standard accounts-payable check for whether to pay early.

Enter an annualised return (CAGR) and the maximum drawdown percentage; the tool computes the *Calmar ratio* = CAGR ÷ |Max Drawdown| — a standard risk-adjusted performance metric for hedge funds, trend-following CTAs and managed futures.

Enter accounts payable, cost of goods sold (COGS) and the accounting period in days. The tool returns DPO = AP × days ÷ COGS — the average number of days a company takes to pay its suppliers, one of the three working-capital metrics alongside DSO and DIO.

Enter total assets, total liabilities and shares outstanding. The tool returns NAV = (assets − liabilities) / shares — the daily price reference for mutual funds, ETFs, REITs and closed-end funds, and the baseline for evaluating market premium/discount to NAV.

Enter customer-acquisition cost (CAC), monthly ARPU and gross margin; the tool returns CAC Payback = CAC ÷ (ARPU × gross margin) — a core SaaS / subscription unit-economics ratio that shows how many months a new customer takes to "pay for themselves".

Enter the asset cost, salvage value, total productive units (lifetime) and units produced this period; the tool returns per-unit depreciation and the period's depreciation expense using the *units-of-production* method — best for assets whose wear scales with use (machinery, fleet mileage, mineral reserves) rather than time.

Enter ARR for two consecutive quarters and the prior quarter's sales-and-marketing spend; the tool returns the SaaS Magic Number = 4 × ΔARR / S&M — a widely cited VC benchmark for go-to-market investment efficiency.

Enter the annual revenue growth rate and the EBITDA / free-cash-flow margin (%); the tool returns Rule of 40 = Growth + Profit Margin and flags whether the business clears the 40% health threshold long used by SaaS investors.

Enter periodic payment PMT, per-period rate r and number of periods n; the tool computes the present and future value of an *annuity due* (payments at the start of each period) using PV = PMT · (1 − (1+r)^−n)/r · (1+r) and FV = PMT · ((1+r)^n − 1)/r · (1+r) — contrasting with the ordinary-annuity formulas used by most calculators.

Enter each firm's market share (%); the tool returns HHI = Σ (sᵢ)² — the standard concentration metric used by the US DOJ/FTC, European Commission, and Hong Kong Competition Commission in merger review and antitrust analysis. HHI < 1 500 = unconcentrated, 1 500–2 500 = moderately, > 2 500 = highly concentrated.

Enter sales revenue, variable cost and fixed cost; the tool returns the Degree of Operating Leverage = Contribution Margin ÷ Operating Income (EBIT) — the expected % change in EBIT for a 1 % change in sales. High DOL = high-fixed-cost structure = greater sensitivity to revenue swings.

Enter total sales + marketing spend for the period and number of new customers acquired; the tool returns CAC = S&M ÷ new customers, plus the LTV/CAC benchmark (≥ 3 is considered healthy SaaS).

Enter revenue and EBITDA — or its building blocks (net income, interest, tax, depreciation, amortisation); the tool returns the EBITDA margin = EBITDA ÷ revenue × 100 %, the standard "cash-generating power" ratio and the comparison base for EV / EBITDA valuation multiples.

Enter intrinsic value and market price; the tool returns Margin of Safety = (Intrinsic − Market) ÷ Intrinsic — Benjamin Graham's cornerstone value-investing metric — together with the maximum buy price that satisfies a target MOS percentage.

Enter starting MRR plus expansion (upsell / cross-sell), contraction (downgrades) and churn; the tool returns *Net Revenue Retention* (NRR / NDR) = (Starting MRR + Expansion − Contraction − Churn) / Starting MRR — the most-watched SaaS retention metric, where > 100 % signals *negative net churn*.

Enter the count at each funnel stage (e.g. visitors → leads → MQLs → SQLs → customers); the tool returns the per-stage conversion rate, overall conversion rate and drop-off — the fundamental marketing / sales / product analytics metric.

Enter the prior session's High, Low and Close; the tool returns the classic Floor-Trader Pivot Point (PP) plus three resistance (R1–R3) and three support (S1–S3) levels — the standard intraday levels used by equity, futures and FX traders.

Enter the loan amount, interest rate, term, property tax and insurance; the tool breaks the monthly payment into Principal, Interest, Taxes and Insurance (PITI) — the more realistic cash-flow figure lenders use to compute the debt-to-income (DTI) ratio.

Enter property price and gross annual rent; the tool returns GRM = price ÷ annual rent and benchmarks the result against typical market bands (4–7 attractive, 8+ expensive) — a quick way to compare investment properties before doing full NOI math.

Pick call or put, enter strike and premium; the tool returns the expiration break-even price, intrinsic value at a given spot, and the maximum loss for a long-option position — the first-line risk-reward check.

Enter principal, annual rate and tenure; the tool returns the standard EMI = P · r · (1+r)ⁿ / ((1+r)ⁿ − 1) monthly payment plus total interest and total payable — the equated-monthly-installment formula used by Indian and global banks for any amortising loan.

Enter impressions and clicks; the tool returns CTR = clicks ÷ impressions × 100% and benchmarks the result against typical industry bands (display 0.05–0.5%, search 2–8%) — a quick read on creative, landing page or keyword pull.

Enter ad spend and the revenue attributed to it; the tool returns ROAS = revenue ÷ spend (also shown as X:1) and benchmarks it against typical break-even floors (most paid channels need ≥ 3:1 to be profitable) — the headline number for any paid-media review.

Tick the nine Piotroski criteria (4 profitability, 3 leverage / liquidity, 2 efficiency); the tool returns the 0–9 F-Score and bands it as weak / moderate / strong — Joseph Piotroski's 2000 fundamental-strength screen, the standard quant filter for value-stock selection.

Enter spot S, strike K, risk-free rate r, time to expiry T and either the call or put price; the tool uses put-call parity *C − P = S − K·e^(−rT)* to solve for the other — the *no-arbitrage identity* of European options, valid without assuming a volatility or lognormal distribution.

Enter cash on hand, monthly spend and monthly revenue; the tool returns *net burn rate* and *runway* in months — the fundamental startup-finance metric that answers "how long before we run out of cash?".

Enter year-1 free cash flow, projection-period growth, horizon N, discount rate r and a perpetual terminal growth g; the tool returns intrinsic value = Σ FCFₜ/(1+r)ᵗ + TV/(1+r)ᴺ via the Gordon-growth terminal — the two-stage DCF used by Buffett, Damodaran and the McKinsey Valuation manual.

Paste a historical return series; the tool returns *historical* (empirical-percentile) and *parametric* (Normal) VaR plus Conditional VaR / Expected Shortfall, scaled to multi-day horizons via the √h rule — the Basel market-risk and fund-manager risk-control standard.

Enter portfolio return R_p, risk-free rate R_f, market return R_m and portfolio β; the tool returns α = R_p − [R_f + β·(R_m − R_f)] — Jensen's 1968 risk-adjusted measure of how much a fund beat the CAPM benchmark, the textbook score for active management.

Enter the asset cost, salvage value, useful life and discount rate; the tool returns EAC = NPV ÷ annuity factor — the standard corporate-finance metric for comparing capital investments with different lifespans (e.g. a 5-year vs 10-year machine) by reducing each to a fair annual rent.

Enter a series of closing prices and a period N (default 20); the tool returns the upper band = N-period high, the lower band = N-period low, the middle = (upper + lower) / 2 and %D (the price's position percentile inside the channel) — Richard Donchian's 1960s breakout system, the original Turtle Traders setup and the simplest indicator in trend-following.

Enter a series of closing prices, a moving-average period N (default 20) and a standard-deviation multiplier k (default 2); the tool returns the middle band SMA, the upper band SMA + k·σ, the lower band SMA − k·σ and %B (the price's relative position inside the channel) — John Bollinger's 1983 volatility / breakout indicator.

Enter a series of closing prices and a period N (default 14); the tool applies Wilder's smoothing to obtain average gain, average loss, RS = avgGain/avgLoss and RSI = 100 − 100/(1+RS) — J. Welles Wilder's 1978 momentum oscillator, with the traditional 70/30 thresholds for overbought / oversold.

Enter a series of closing prices and three EMA periods (fast / slow / signal — traditionally 12 / 26 / 9); the tool returns the MACD line = EMA₁₂ − EMA₂₆, signal line = EMA₉(MACD) and histogram = MACD − signal — Gerald Appel's 1970s trend-and-momentum indicator.

Enter a closing-price series, a look-back period N (default 14) and a %D smoothing period M (default 3); the tool returns %K = 100·(Close − LowestLow_N) / (HighestHigh_N − LowestLow_N) and %D = SMA_M(%K) — George Lane's 1950s momentum oscillator with the traditional 80 / 20 overbought / oversold thresholds.

Enter a closing-price series and a look-back period N (default 14); the tool returns %R = −100·(HighestHigh_N − Close) / (HighestHigh_N − LowestLow_N) — Larry Williams' 1973 momentum oscillator on a [−100, 0] scale with the traditional −20 / −80 overbought / oversold thresholds.

Enter a series of highs, lows and closes plus the Wilder period N (default 14); the tool returns +DI, −DI and ADX = Wilder-smoothed(DX, N), where DX = 100 · | +DI − −DI | ⁄ ( +DI + −DI ) — J. Welles Wilder's 1978 *non-directional* trend-strength indicator (ADX > 25 marks a clear trend, < 20 marks a range / no trend).

Enter the capital paid in plus the cash distributions received and the residual value of the investment; the tool returns the *Equity Multiple* = (Distributions + Residual Value) / Paid-In Capital — the private-equity / real-estate *MOIC* and TVPI, the simplest "how many times my money came back" measure.

Enter EBIT (operating profit) and interest expense; the tool returns *Times Interest Earned* = EBIT / Interest — the core credit-analysis and bond-rating solvency ratio measuring how many times operating profit covers the interest bill (< 1.5 is risky, > 3 is healthy).

Enter return on equity (ROE) and the retention ratio (1 − dividend payout); the tool returns the *Sustainable Growth Rate* = ROE × b — the highest sales-growth rate a firm can sustain without issuing new equity or changing leverage, the central output of Higgins' SGR model.

Enter the previous session's high H, low L and close C; the tool returns three families of pivot levels — *classic floor-trader*, *Camarilla* and *Fibonacci* support / resistance lines — the day-trader's reference for entries, exits and stop placement.

Enter N periods of high / low / close prices; the tool returns *Williams %R = −100 · (HH − C) ⁄ (HH − LL)* — Larry Williams' (1973) momentum oscillator bounded in [−100, 0], with values above −20 marking overbought and below −80 marking oversold. The mirror image of the Stochastic Oscillator.

Enter your net zakatable assets (cash, gold, silver, investments) and the nisab threshold to calculate the zakat due, normally 2.5%.

Enter the balance and rate of several loans to get the balance-weighted average interest rate — commonly used to assess debt or student-loan consolidation.

Combine several loans with different balances and rates into a single balance-weighted blended (weighted-average) interest rate — handy for comparing consolidation or refinancing.

Compute the accounts receivable turnover ratio and average collection period (DSO) from net credit sales and average receivables to gauge collection efficiency.

Compute the real value of a rewards redemption (cents per point) from the cash price, taxes and points required, to judge whether it is worth it.

Calculate the contribution margin per unit and the contribution margin ratio from selling price and variable cost per unit.

Compute the degree of financial leverage (DFL) from EBIT and interest expense to gauge how earnings changes amplify EPS.

Compute commission and total pay from sales and a commission rate, with support for a flat rate or a tiered (threshold) structure.

Use the 20/4/10 rule (20% down, max 4-year loan, car costs under 10% of income) to find the car price you can realistically afford.

Estimate cost per API call and monthly spend from input/output token counts, price per million tokens and monthly request volume.

From a swing high and low, compute the 23.6%, 38.2%, 50%, 61.8% and 78.6% retracement levels plus extension targets.

From the overdue amount, interest/penalty rate and days late, work out the late fee and total due.

Compare paying a subscription annually vs monthly — see the yearly cost of each, how much and what percent you save, and the equivalent free months.

Enter your age and a rule (100/110/120 minus age) to get a suggested stocks-vs-bonds split as percentages and amounts.

Enter miles/km driven and a per-unit rate to work out total mileage reimbursement, with optional two-tier rates (e.g. UK AMAP 45p/25p).

Split a lump sum across staggered fixed-deposit terms and see each rung’s amount, maturity and total interest.

Estimate UK income tax, take-home pay and effective rate using the 2024/25 personal allowance and tax bands.

Compute US Social Security and Medicare self-employment tax (15.3%) and the deductible half from net self-employment income.

Compute the IRA/401(k) required minimum distribution from a year-end balance and age using the IRS Uniform Lifetime Table.

Estimate UK inheritance tax due using the nil-rate band and 40% rate on the estate above the threshold.

Estimate Australian federal income tax, the Medicare levy and your average rate from taxable income using the ATO resident tax brackets.

Estimate US federal income tax, marginal and effective rates from gross income and filing status using the IRS brackets and standard deduction.

Estimate Canadian federal income tax from taxable income using the CRA federal brackets and basic personal amount (provincial tax excluded).

Compute UK Stamp Duty Land Tax on a residential purchase from the price using the England & Northern Ireland SDLT bands, with first-time-buyer relief and the additional-property surcharge.

Estimate US federal capital gains tax from cost basis, sale price, holding period and other income using the IRS long-term and short-term rates.

Estimate Singapore resident personal income tax from chargeable income using the IRAS progressive tax brackets.

From monthly spend, reward rate and annual fee, work out the net yearly rewards and the spend needed to break even.

Validate an international bank account number (IBAN) with the ISO 13616 mod-97 checksum.

Spread the face rent, lease term and rent-free months into a net effective monthly rent, total payable and discount percentage.

Compare interest on your current card against a balance transfer’s fee plus promo rate to see your net savings.

Estimate your employer 401(k) match from your contribution rate and the plan formula, and whether you are leaving free money on the table.

Calculate labour cost as a percentage of revenue from total wages and sales, for managing staffing costs.

Compute utilization rate and effective bill rate from billable versus available hours, for consultants and freelancers.

Enter the decimal odds for both sides and your total stake to check for an arbitrage opportunity and split the stake to lock in a guaranteed profit.

Strip the bookmaker margin (vig) from two-way odds to recover the fair implied probability and fair odds of each outcome.

From your original stake, original odds and the current opposite odds, work out the hedge stake and the profit locked in whichever way the result goes.

Compute the debt yield (NOI ÷ loan amount) that commercial real-estate lenders use, and back out the maximum loan for a target debt yield.

Compute the loan constant (annual debt service ÷ loan principal) from the interest rate and term to gauge the yearly debt burden per dollar borrowed.

Compute a covered call’s static return, if-called return and downside protection from stock price, strike and premium.

For semi-retirement with part-time income, compute the portfolio you need and how far you still are from it.

From the gas limit, gas price (gwei) and token price, compute a transaction fee in both the native coin and fiat.

Enter an amount and get the fewest bills and coins that make it up across selectable denominations — handy for making change, counting a till and preparing a cash float.