Convert hp to kw
PrintHorsepower to Kilowatt Conversion Table
| Horsepower (hp) | Kilowatt (kW) |
|---|---|
| 1 hp | 0.7456999 kW |
| 5 hp | 3.7284994 kW |
| 10 hp | 7.4569987 kW |
| 20 hp | 14.913997 kW |
| 50 hp | 37.284994 kW |
| 100 hp | 74.569987 kW |
| 150 hp | 111.85498 kW |
| 200 hp | 149.13997 kW |
| 500 hp | 372.84994 kW |
Horsepower and kilowatts are the two standard units used globally to express engine performance, electric motor output, HVAC heating/cooling rates, and mechanical machinery capability. While horsepower (hp) is the traditional customary power unit used in car marketing, lawnmowers, and marine engines across North America and the UK, the kilowatt (kW) is the official International System of Units (SI) power standard used across Europe, Asia, electric vehicle (EV) specifications, and global engineering.
Our free online Hp to Kw Converter provides instant, high-precision power conversions in both directions:
- Metric Horsepower (PS / CV) to kW: Multiply metric hp by
0.73549875(or divide by1.3596216). - Mechanical Horsepower (Imperial hp) to kW: Multiply imperial hp by
0.74569987(or divide by1.341022). - Electric Motor Horsepower to kW: Multiply electric hp by
0.746(exact 746 Watts standard).
Comparing the Different Types of Horsepower
Because horsepower was standardized differently across countries and industries, converting hp to kW depends on the specific horsepower type being measured:
| Horsepower Type | Standard Symbols | Power in Watts (W) | Kilowatt Conversion Formula |
|---|---|---|---|
| Metric Horsepower | PS (German), CV (French), pk, hk | 735.49875 W (75 kgf·m/s) | kW = hp × 0.73549875 |
| Mechanical / Imperial Horsepower | hp, hp(I), bhp | 745.69987 W (550 ft·lbf/s) | kW = hp × 0.74569987 |
| Electric Motor Horsepower | hp(E) | 746.00000 W (exact) | kW = hp × 0.74600000 |
| Boiler Horsepower | hp(S), BHP | 9,809.50000 W (34.5 lb water/hr) | kW = hp × 9.80950000 |
Step-by-Step Calculation Example
To explicitly convert 15 metric horsepower (PS) to kilowatts, you must multiply the HP value by the exact European metric conversion factor.
| Math Step | Execution Logic | Calculated Value |
|---|---|---|
| Step 1: Input HP | Identify the starting horsepower value. | 15 hp |
| Step 2: Conversion Factor | Select the Metric PS to kW multiplier. | 0.73549875 |
| Step 3: Final Multiplication | 15 × 0.73549875 |
11.03 kW |
Metric Horsepower to Kilowatt Conversion Table
Below is a quick reference lookup table converting engine and motor outputs from 0.01 hp up to 1,000 hp:
| Horsepower (Metric PS) | Kilowatts (kW) | Automotive & Machinery Benchmark |
|---|---|---|
| 0.01 hp | 0.007355 kW | 7.35 Watts (small cooling fan motor) |
| 0.10 hp | 0.073550 kW | 73.55 Watts (aquarium water pump) |
| 1.00 hp | 0.735499 kW | 1.0 Metric Horsepower Benchmark (735.5 W) |
| 2.00 hp | 1.470998 kW | Standard workshop air compressor motor |
| 5.00 hp | 3.677494 kW | Lawnmower / outboard boat motor |
| 10.00 hp | 7.354988 kW | Household backup electric generator |
| 20.00 hp | 14.709975 kW | Riding lawn tractor / small utility tractor |
| 50.00 hp | 36.774938 kW | Compact agricultural tractor engine |
| 100.00 hp | 73.549875 kW | Compact economy hatchback car engine (≈74 kW) |
| 200.00 hp | 147.099750 kW | Midsize sedan / crossover SUV engine (≈147 kW) |
| 500.00 hp | 367.749375 kW | High-performance sports car engine (≈368 kW) |
| 1,000.00 hp | 735.498750 kW | Hypercar / Tri-motor Electric Vehicle (EV) benchmark |
History & Engineering: James Watt vs. Sir William Siemens
James Watt and the Origin of Horsepower
The term horsepower was coined in the late 18th century by Scottish engineer James Watt to market his improved steam engines to mine owners. To demonstrate how many horses his engine could replace, Watt calculated that a strong draft pit pony turning a 12-foot mill wheel 2.4 times per minute applied 180 pounds-force of pull. He increased the number by 50% to establish the standard of 33,000 foot-pounds per minute (550 ft·lbf/s), creating mechanical horsepower. Metric countries later standardized this as lifting 75 kg against gravity by 1 meter in 1 second (75 kgf·m/s = 735.5 Watts), known in Germany as Pferdestärke (PS) and France as cheval-vapeur (CV).
The SI Kilowatt (kW) Standard
In 1882, engineer Sir Charles William Siemens proposed naming the SI unit of power after James Watt. In 1908, the watt (W) and kilowatt (kW) were adopted as the universal scientific unit of power, defined as 1,000 Joules of energy transferred per second (1 kW = 1,000 J/s).
To calculate mechanical horsepower and torque natively, visit our Horsepower Calculator or Engine Horsepower Calculator. For electrical circuit power calculations, check our Ohm’s Law Calculator or Electricity Calculator. For general unit transformations, explore our Conversion Calculator.
Frequently Asked Questions (FAQ)
How many kilowatts are in 1 horsepower?
For metric horsepower (PS), 1 hp equals 0.7355 kW. For imperial mechanical horsepower, 1 hp equals 0.7457 kW. For electric motors, 1 hp equals 0.746 kW.
How many horsepower are in 100 kW?
100 kW converts to 100 × 1.35962 = 135.96 metric horsepower (PS), or 100 × 1.34102 = 134.10 imperial mechanical horsepower.
Why do European car specs list engine power in kW instead of hp?
European Union directives mandate that all automotive specifications declare power in kilowatts (kW) as the official SI unit. However, marketing brochures often list both kW and metric horsepower (PS) to appeal to consumers.
What is a 500 hp supercar rating in kW?
A 500 hp sports car produces 500 × 0.7355 = 367.75 kW of power.