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Casino House Edge / RTP Expected Loss Calculator

The **house edge** is the long-run percentage of every wager the casino keeps; the slot-machine framing **Return to Player (RTP)** is its mirror — RTP + house edge = 100 %. **Expected loss formulas**: per round = bet × edge; per hour = round × rounds/hour; per year = hourly × hours/session × sessions/year. **Typical house edges**: American roulette 5.26 %, European roulette 2.70 %, baccarat banker 1.06 %, blackjack basic strategy ~0.5 %, craps pass line 1.41 %, slots 2–15 % (regulated markets, RTP 85–98 %), keno 25–30 %, state lotteries 30–50 %. **Uses**: (1) **bankroll & stop-loss** — back into a per-session bet and round limit from an affordable annual entertainment budget; (2) **game comparison** — for the same wager which game bleeds the least over time; (3) **dispel the "I am winning" illusion** — single-night variance is huge, five winning nights in a row do not beat a 5 % edge; (4) **responsible gambling** — convert the *abstract edge* into a *concrete $/year* you can compare to other entertainment spend.

Expected loss per round

Expected loss per hour

Expected loss per session

Expected loss per year

This is the *long-run expected value* (law of large numbers); a single night swings far wider. Gambling is entertainment spending, not income — set a budget and stop-loss in advance and only bet money you can afford to lose. If gambling is becoming a problem, contact GamCare (UK), the National Council on Problem Gambling 1-800-522-4700 (US) or the Hong Kong Ping Wo Fund hotline 1834 633.

Formula

Notation: bet = wager per round rph = rounds (spins / hands / bets) per hour edge = house edge in percent (0–100) h/s = hours per session s/y = sessions per year rtp = 100 % − edge Expected loss: E[loss/round] = bet × (edge / 100) E[loss/hour] = E[loss/round] × rph E[loss/session] = E[loss/hour] × (h/s) E[loss/year] = E[loss/session] × (s/y) Total wagered (which is NOT what you lose!): wagered/year = bet × rph × (h/s) × (s/y) Example: $5 × 50 spins/h × 5.26 % American roulette × 2 h/session × 52 sessions/yr → $13.15/h, ≈ $1 368/yr expected loss, $26 000 wagered.

Frequently asked

I play $1 000 of slots in Macau every week — what is my real expected loss per year?

**Estimate the parameters first**: typical Macau slot RTP is 90–94 % (i.e. 6–10 % house edge); use 8 % as the midpoint. $1.50 per spin × 600 spin/h × 2 h per session = $1 800 wagered per session (note: the $1 000 you walk in with cycles through the slot multiple times — *total wagered* is much higher than starting bankroll). **Expected loss**: (a) per session: $1 800 × 8 % = **$144**; (b) per year (52 sessions): **$7 488**; (c) but variance is huge — a single night can win $500 or lose $1 000+, and the realised annual loss has ~70 % probability of falling in $5 000–$15 000. **Compare other games at the same $1 800/session wager**: baccarat banker 1.06 % → $19/session, $986/year; blackjack basic strategy 0.5 % → $9/session, $468/year. **Bottom line**: (1) slots are the most negative-EV way to spend entertainment money; (2) $7 488/yr buys roughly six weeks of staycation budget — whether that is worth it is your call; (3) switching to baccarat or blackjack can cut long-term cost 10–15×; (4) set a per-session stop-loss ≤ $300 to avoid blow-up nights.

Slot RTP 95 % vs blackjack RTP 99 % — same dollars wagered, why is the loss so different?

**Because the edge interacts with rounds-per-hour (rph) — and they differ wildly**. Compare at the same $100/hour "wagering intensity": (a) **slot RTP 95 % (5 % edge)**: $1 × 600 spin/h, wagered/h = $600, expected loss = $600 × 5 % = **$30/h**; (b) **blackjack RTP 99 % (1 % edge)**: $25 × 70 hand/h, wagered/h = $1 750, expected loss = $1 750 × 1 % = **$17.50/h**. **Paradox**: blackjack wagers *more* per hour (the $25 hand is larger than the $1 spin) but the edge is 5× smaller — so net loss is lower. **Caveat**: blackjack requires skill — without the basic-strategy chart memorised (free online), untrained play gives up another 2–3 %, making it *more expensive* than the slot. **Bottom line**: (1) RTP / edge is a *per-wager* number that only matters once multiplied by rph; (2) slots = high rph + medium edge → a long-run -EV machine; (3) blackjack = low rph + tiny edge → the most player-friendly game *for the basic-strategy player*; (4) casinos know this — which is why slots are ~70 % of casino floor & revenue, not blackjack.

I have won five weeks in a row — have I found a system?

**Almost certainly no — you are on the lucky tail of normal variance**. **The math**: with a 5 % house edge and typical per-session σ ≈ 6–10× EV, five winning sessions in a row have probability ≈ (0.35)⁵ ≈ **0.5 %** (about 1 in 200 players). If you are that 1 in 200, you live in a probable universe — but statistically you cannot distinguish "real edge" from "lucky variance" without 200+ sessions (~2 years of intensive play). **What does actually beat the casino**: (1) **card counting (blackjack)** — can flip a 1 % edge to 0.5–1.5 % player advantage, but requires *perfect* Hi-Lo execution + bet spread; amateurs still lose, and counters get back-roomed and shared across casino blacklists; (2) **wearable-computer roulette prediction** — early 1990s only, now defeated by very fast "no more bets" calls and chip-tracking software; (3) **poker** — skill vs other players, the only consistently +EV casino game (though the rake means overall players are -EV against the room). **Conclusion**: (a) five winning weeks is luck, not a system; (b) raising the bet just accelerates regression to EV; (c) the belief you have "cracked it" is a classic early sign of *gambling problem*; (d) bank the winnings, stop for 4 months, then "test" again — if the edge is real it will reappear; 99 % of the time you will find the original streak was luck.

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Enter the nightly room rate, occupancy tax %, per-night resort / city fee and number of nights — the tool returns the pre-tax subtotal, taxes, fees, grand total and per-person share. Essential for comparing booking quotes and filing business-trip expenses.

Cake Servings Calculator (Round / Square → Number of Guests)

Enter cake shape (round / square / rectangular) and size (diameter or side in inches or cm); the tool applies the Wilton industry-standard cut to return "wedding" (small), "party" (medium) and "generous" (large) servings — invaluable for weddings, birthday parties and event catering.

Prorated Annual Leave Calculator (Join / Leave Date)

Enter the contractual annual leave entitlement, join date and (optionally) leave date — the tool returns the pro-rated leave for the part-year, by months or by calendar days. A universal framework that fits any local labour law or company policy.

Dimensional Weight (DIM) Shipping Calculator

Enter the package length × width × height and the actual weight, pick a carrier divisor (UPS / FedEx / DHL / international), and the tool returns the dimensional weight (DIM), the chargeable weight (max of actual vs DIM) and density — the standard way every major courier prices a parcel.

Yarn Skein Quantity Calculator (Knitting & Crochet)

Enter the total yarn length required by your pattern (yards or metres) and the length per skein; the tool returns the number of skeins to buy with a chosen safety margin (5 %/10 %/15 %), the leftover yarn and total cost — the must-do check before walking into a yarn shop.

Fabric Yardage Calculator (Pieces × Dimensions ÷ Width)

Enter how many pieces you need, each piece's length × width and your fabric width (45"/54"/60" or custom); using a one-way single-cut layout the tool returns required yardage (yards / metres) with adjustable shrinkage and pattern-match margin, and estimates total fabric cost — the standard pre-shop check for sewing, home décor, cosplay and curtain projects.