kW ⇄ Horsepower Converter (kW / HP / PS)
Kilowatts (kW) and horsepower (hp / PS / BHP) are the everyday units for cars, motorcycles, generators and power tools, but "horsepower" actually has several distinct definitions — US/UK mechanical hp, European metric PS, and dyno-measured BHP. This tool shows the equivalent value in all six common units side by side and lists the exact conversion factor for each.
Please enter a valid number
All-units value
Common reference: 1 kW ≈ 1.341 hp ≈ 1.360 PS. Mechanical hp and BHP are numerically identical (both 745.6999 W); they differ only by where the measurement is taken (flywheel vs crankshaft). Metric PS = 75 kgf·m/s = 735.49875 W exact, used on European / Japanese engine specs.
- kW SI unit used for EVs, household appliance ratings, and solar panel output.
- hp US / UK car & power-tool ratings — defined as 550 ft·lbf/s.
- PS European (PS) / French (CV) / Japanese horsepower spec for engines.
- BHP Power at the crankshaft (before losses); numerically equal to mechanical hp.
—
Formula
1 hp (mechanical) = 745.6998715822702 W ; 1 PS = 75 kgf·m/s = 735.49875 W (exact) ; 1 BHP ≡ 1 mechanical hp ; 1 ft·lbf/s = 1.3558179483314 W
- · Mechanical horsepower (hp, imperial) was defined by James Watt as 550 ft·lbf/s ≈ 745.6999 W and is the default for US / UK car ratings.
- · Metric horsepower (PS, Pferdestärke / CV, cheval-vapeur) is exactly 75 kgf·m/s = 735.49875 W — the dominant unit in European and Japanese spec sheets. Numerically about 1.4% larger than mechanical hp.
- · BHP (Brake Horsepower) is engine output measured on a brake dynamometer; numerically identical to mechanical hp by definition. The location of measurement (crankshaft vs flywheel) differs, but "200 BHP" ≡ "200 hp" for conversion purposes.
- · Electrical horsepower is occasionally defined as exactly 746 W for motor nameplates; the difference is ~0.04%, so 745.7 W is fine for most uses.
- · Caveat: published "gross hp" is engine-output, while wheel horsepower (WHP) at the drive wheels is 15–25% lower due to driveline losses.
- · References: NIST SP 811 App. B.8 (mechanical hp); ISO 80000-4:2019 *Quantities and units — Mechanics*; BIPM SI Brochure §2.3.3 (watt).
Frequently asked
How different are hp and PS?
PS (metric) is about 1.4% smaller than hp (mechanical): 1 hp = 1.01387 PS, or 1 PS = 0.98632 hp. A 200-hp US car ≈ 202.7 PS; a "200 PS" European version is only 197.3 hp. For engineering you can't treat them as equal; in marketing copy people usually do.
BHP vs WHP — what is the difference?
BHP (brake horsepower) is engine output measured on a brake dynamometer with no driveline losses; WHP (wheel horsepower) is measured at the wheel hub on a chassis dyno after losses through gearbox, driveshaft, differential and tyres (typically 15–25%). Spec sheets are usually BHP; owners reading from a chassis dyno see WHP. This tool treats BHP and hp as numerically identical, because both share the same SI conversion factor — drivetrain losses are a physical measurement issue, not a unit conversion.
Why is 1 kW ≈ 1.34 hp in some sources and 1.36 in others?
Two common values: 1 kW = 1.341022 hp (mechanical / imperial) or 1.359622 PS (metric horsepower). European sources tend to use PS (1.36); US/UK sources use mechanical hp (1.34). The discrepancy is ~1.4% — that is already 2 hp for a 100-kW motor, so formal reports must specify "mechanical/imperial" or "metric/PS/CV".
Related tools
Length Unit Converter
Cm, m, km, in, ft, yd, mi — common length units, converted instantly.
Temperature Converter
Convert between Celsius (°C), Fahrenheit (°F) and Kelvin (K) instantly.
Shoe Size Converter (US / UK / EU / CM)
Enter your foot length or a size in any system to see the equivalent US / UK / EU and centimetre sizes.
Paper Size Reference
Pick a paper size (A0–A10, B / C series, Letter, Legal, card sizes) to see its mm / cm / inch / pixel dimensions.
Number Base Converter (Binary / Octal / Decimal / Hex)
Convert a number simultaneously between binary, octal, decimal and hexadecimal — useful for programmers, students and electronics work.
Aspect Ratio & Screen Size Calculator
From an aspect ratio and one side, find the other; or from a diagonal and ratio, get real width and height (4:3, 16:9, 21:9 …).
Data Storage Unit Converter (B/KB/MB/GB/TB)
Convert between bytes, KB, MB, GB, TB and PB — distinguishing decimal (1000-base, drive labels) from binary (1024-base, OS-reported).
RGB ↔ HEX ↔ HSL Color Converter
Convert between HEX (#RRGGBB), RGB(0–255) and HSL(0–360, 0–100, 0–100) instantly — with a live colour preview swatch.
Tire Size Calculator (Spec / Diameter / Speedometer Error)
Convert a P-metric tire spec (e.g. 225/65R17) into sidewall height, overall diameter, circumference and revolutions per km — and compare against a reference size to see speedometer error.
Energy Unit Converter (J / kJ / cal / kcal / kWh / BTU / Wh)
Convert between joules, kilojoules, calories, kilocalories, kilowatt-hours, BTU and watt-hours in a single view — for nutrition labels, electricity bills, heating and fuel comparisons.
Pressure Unit Converter
Convert between Pa, kPa, bar, mbar, atm, psi, mmHg, Torr and inHg in a single view — all the everyday pressure units.
Torque Unit Converter
Convert between N·m, kgf·m, kgf·cm, lbf·ft, lbf·in and ozf·in — all the torque units used on torque wrenches, bicycle bolts and car service specs.
Angle Unit Converter
Convert between degrees, radians, gradians, turns, arcminutes, arcseconds, milliradians and NATO mil — with live sin/cos/tan values for reference.
Fuel Economy Converter (MPG ⇄ L/100km)
Convert between L/100km, km/L, US MPG and UK (imperial) MPG — compare car efficiency figures across regions without arithmetic.
Power Unit Converter
Convert between W, kW, MW, mechanical horsepower (hp), metric horsepower (PS), BTU/hr, ft·lbf/s, cal/s, kcal/h and refrigeration tons in one view.
px ↔ rem ↔ em Converter
Pick a root font-size (defaults to 16 px) and convert any CSS pixel, rem, em, percentage or point value into the others, with a reference table for common sizes.
Alcohol ABV ↔ Proof Converter & Standard Drinks Calculator
Convert alcohol by volume (ABV %) to US proof and UK proof, plus compute grams of pure alcohol and "standard drinks" per pour for US / UK / AU / HK.
Bandwidth & Throughput Converter (Mbps ↔ MB/s)
Convert network bandwidth (kbps, Mbps, Gbps) to file-transfer rate (KB/s, MB/s, MiB/s) and estimate how long a given file size takes.
Weight / Mass Unit Converter
Kilograms, grams, milligrams, pounds, ounces, stones, tonnes, jin and tael — common mass units, converted instantly.
Battery mAh ↔ Wh Converter (Power Bank Airline Rules)
Enter battery capacity (mAh) and voltage (V) to get watt-hours (Wh) instantly — with a live IATA airline check (100 Wh / 160 Wh cut-offs).
International Bra Size Converter
Enter underbust and bust (or pick a local size) to convert bra sizes across US, UK, EU, AU and JP standards.
International Ring Size Converter
Enter inner circumference (mm) or diameter to cross-reference US, UK, EU, JP and HK ring sizes.
Area Unit Converter
Square metres, hectares, acres, square feet, square miles and more — common area units, converted instantly.
Volume / Capacity Unit Converter
Litres, millilitres, cubic metres, US and imperial gallons, quarts, pints, fluid ounces, cups, tablespoons and teaspoons — converted instantly.
Speed Unit Converter
Convert freely between km/h, mph, m/s, ft/s, knots and Mach number.
Color Contrast Ratio (WCAG) Calculator
Enter foreground and background hex colors to compute the WCAG 2.x contrast ratio (1:1 to 21:1) and see whether the pair passes AA / AAA accessibility levels for normal and large text.
AWG Wire Size Calculator
Look up the diameter (mm), cross-sectional area (mm²), resistance per kilometre and safe ampacity for any American Wire Gauge (AWG) size — handy for low-voltage wiring design.
Frequency Unit Converter (Hz / kHz / MHz / GHz)
Convert between Hz, kHz, MHz, GHz, THz, RPM and BPM — one input fills every other unit instantly.
Force Unit Converter (N / kN / lbf / kgf / dyne)
Convert between newtons (N), kilonewtons (kN), pound-force (lbf), kilogram-force (kgf), dyne and ounce-force (ozf) — bridging SI, imperial and CGS force units used in physics and engineering.
Magnetic Flux Density Converter (T / mT / µT / Gauss)
Convert magnetic flux density between tesla (T), millitesla (mT), microtesla (µT), gauss (G) and milligauss (mG) — handy for comparing MRI fields, Earth field, speakers and lab magnets across very different scales.
Volumetric (Dimensional) Weight Calculator (Air / Courier)
Enter parcel length × width × height and DIM divisor (IATA air 6000 cm³/kg, express 5000, UPS/FedEx US 139 in³/lb) to compute volumetric weight and compare it with actual weight to find the chargeable weight.
Polar ↔ Cartesian Coordinate Converter
Convert Cartesian (x, y) ↔ polar (r, θ) coordinates in either direction with a degree/radian toggle — useful for math, physics, engineering and game-development work.
Astronomical Distance Converter (ly / pc / AU / km)
Enter any distance and the tool converts it across metres, kilometres, miles, Earth–Moon distance, astronomical units (AU), light-years, parsecs and light-travel time — useful for astronomy, science fiction and classroom prep.
Map Scale Distance Converter
Enter a scale ratio (e.g. 1:25 000) and a measured map distance; the tool returns the real-world distance, or works in reverse from real distance to map distance — useful for hiking, map reading and town planning.
DMS ↔ Decimal Degrees Converter
Two-way conversion between degrees–minutes–seconds (D° M′ S″) and decimal degrees — the standard need when juggling GPS coordinates, astronomy, surveying and marine navigation. Supports signed values for south latitude and west longitude.
Hat Size Converter (Head Circumference → US/UK/EU/JP)
Enter your head circumference (cm or inches); the tool maps it to US (fitted and fractional), UK, EU (cm) and Japanese hat sizes plus the S/M/L/XL range — useful for buying New Era caps, fedoras, baseball caps and helmet liners online.
Lumens ⇄ Lux Converter (lm ⇄ lx)
Enter the luminous flux (lumens, lm) of a fixture and the lit area; the tool returns the illuminance (lux = lm/m²) and can solve for the lumens required to hit a target lux — used for room lighting design, photography, grow lights and workplace illuminance planning.