HP to KW Converter (Mechanical Horsepower)
Convert horsepower to kilowatts in one step. This converter uses mechanical (imperial) horsepower, the standard in the US and UK, and shows metric horsepower (PS) as a side value.
Kilowatts = Horsepower × 0.7456998716
HP to KW Formula
One mechanical horsepower is defined as 550 foot-pounds per second, which equals 745.69987158 watts, so hp × 0.7456998716 gives kilowatts. To convert kilowatts to horsepower, divide by 0.7456998716 (or multiply by about 1.341022). Standard used: mechanical (imperial) horsepower, 1 hp = 745.7 W. Metric horsepower (PS) is slightly smaller at 735.49875 W.
About Horsepower and Kilowatts
Horsepower was introduced by James Watt in the 18th century to compare steam engines with draft horses. Several versions exist: mechanical (imperial) horsepower is 745.7 W, metric horsepower (PS, CV or pk) is 735.49875 W, and electrical horsepower is taken as 746 W. A kilowatt is 1,000 watts and is the SI unit used for engine and motor power in most of the world. Always check which horsepower a specification uses, because the difference is about 1.4%.
How to Convert HP to KW
- Enter the power in mechanical horsepower. Decimals such as 12.5 are fine.
- The answer in kilowatts appears instantly, or press Convert Now. Watts, metric horsepower (PS) and electrical horsepower are shown as side values.
- Use Swap Units to convert kilowatts to horsepower, Copy Result to copy the answer, or Clear to start again.
By hand: multiply the horsepower by 0.7457. A quick estimate is to take three quarters of the hp figure: 200 hp is about 150 kW (exact: 149.139974 kW). A power rating cannot be negative, so only zero and positive values are accepted.
Practical Examples
- Family car: 150 hp × 0.7456998716 = 111.854981 kW.
- Sports car: 400 hp is 298.279949 kW.
- Pickup truck engine: 300 hp is 223.709961 kW.
- Water pump motor: 5 hp is 3.728499 kW.
- Lawn mower: 7 hp is 5.219899 kW.
HP to KW – Common Values
Quick reference for frequently used conversions
| Mechanical HP | Kilowatts (kW) | Watts (W) |
|---|---|---|
| 0.5 hp | 0.37285 kW | 372.85 W |
| 1 hp | 0.7457 kW | 745.7 W |
| 2 hp | 1.4914 kW | 1,491.4 W |
| 3 hp | 2.2371 kW | 2,237.1 W |
| 5 hp | 3.728499 kW | 3,728.5 W |
| 7.5 hp | 5.592749 kW | 5,592.75 W |
| 10 hp | 7.456999 kW | 7,457 W |
| 20 hp | 14.913997 kW | 14,914 W |
| 50 hp | 37.284994 kW | 37,284.99 W |
| 75 hp | 55.92749 kW | 55,927.49 W |
| 100 hp | 74.569987 kW | 74,569.99 W |
| 150 hp | 111.854981 kW | 111,854.98 W |
| 200 hp | 149.139974 kW | 149,139.97 W |
| 300 hp | 223.709961 kW | 223,709.96 W |
| 400 hp | 298.279949 kW | 298,279.95 W |
| 500 hp | 372.849936 kW | 372,849.94 W |
| 1000 hp | 745.699872 kW | 745,699.87 W |
Where and Why This Conversion Is Used
Horsepower is still the headline figure for engines in the US and UK, while kilowatts are standard in specifications, regulations and electric drive systems elsewhere.
- Cars and motorcycles: comparing engine output across markets, and reading the power of electric vehicles in kW.
- Industrial motors and pumps: nameplates may list hp or kW, and electricity use is billed in kW and kWh.
- Generators and equipment: sizing a generator or compressor against the load in kilowatts.
- Marine and agriculture: outboards and tractors are often rated in hp.
- Tax and regulation: some countries use kW for registration and vehicle taxation.
For other conversions see the KG to LBS Converter and the MPH to KPH Converter.