Type an engine or motor rating in horsepower and get kilowatts at once, or switch direction to turn kW into hp. Choose mechanical, metric (PS) or electrical horsepower.
Mechanical hp = 745.699872 W, metric hp = 735.49875 W, electrical hp = 746 W. Runs in your browser. Nothing you type is sent anywhere.
This horsepower to kw converter is for car buyers, mechanics, engineers and students comparing power ratings. US and UK car adverts often quote hp, European papers quote PS and kW, and electric motor plates use kW or electrical hp. Pick the type you have and the tool uses its exact factor, so you can compare like with like.
How Do You Convert Horsepower to kW?
To convert horsepower to kilowatts, multiply mechanical horsepower by 0.7457, because 1 hp is 745.7 watts. For example, a 150 hp engine × 0.7457 = 111.85 kW. Metric horsepower (PS) uses 0.7355, so 150 PS is 110.32 kW. To go back, divide kW by 0.7457, so 100 kW is 134.1 hp.
Why Are There Different Kinds of Horsepower?
There are different kinds because horsepower was defined separately in Britain, in Germany and France, and for electric motors, and each definition gives a slightly different number of watts.
Mechanical horsepower, also called imperial hp, was set by James Watt as 550 foot pounds per second, which is 745.699872 W. Metric horsepower, written PS in Germany or ch and CV in France, Italy and Spain, is 75 kilogram force meters per second, exactly 735.49875 W. Electrical horsepower for motors is defined as exactly 746 W. The kilowatt is 1,000 watts, the SI unit of power, and it is the unit used for vehicle power in EU type approval.
1 PS (metric hp) = 75 kgf·m/s = 735.49875 W
1 hp (electrical) = 746 W
kW = hp × 0.745700 hp = kW × 1.341022
Because 550 ft·lbf/s is based on the international foot and pound, the mechanical hp works out to 745.69987 W, which most tables round to 745.7 W. The tool keeps the full value. The three types differ by less than 1.5 percent, so for a 150 unit engine the spread is about 1.6 kW.
What Is the Horsepower to kW Conversion Table?
Values from this tool, rounded to 2 decimal places:
| Power | Mechanical hp to kW | Metric PS to kW | Electrical hp to kW |
|---|---|---|---|
| 1 | 0.75 | 0.74 | 0.75 |
| 5 | 3.73 | 3.68 | 3.73 |
| 10 | 7.46 | 7.35 | 7.46 |
| 50 | 37.28 | 36.77 | 37.3 |
| 100 | 74.57 | 73.55 | 74.6 |
| 150 | 111.85 | 110.32 | 111.9 |
| 200 | 149.14 | 147.1 | 149.2 |
| 300 | 223.71 | 220.65 | 223.8 |
| 500 | 372.85 | 367.75 | 373 |
Is PS the Same as hp?
No, 1 PS is about 1.4 percent smaller than 1 mechanical hp, so the same engine has a higher number in PS than in hp.
A 100 kW engine is 134.1 hp but 135.96 PS. Car makers in Europe often quote PS because the figure looks a little bigger. In everyday talk the gap rarely matters, but for spec sheets and tax forms, check which unit is meant. Brake horsepower, or bhp, is power measured at the crankshaft and uses the mechanical hp unit. For electric devices you can work out current with the watts to amps converter, and running costs with the electricity cost calculator.
Worked Example
A buyer compares a US advert for a 150 hp car with a German one listed in kW. Type 150 with Horsepower (hp) selected: the tool shows 111.85 kW, which is 111,855 watts or 152.08 PS. Switching the type to Metric horsepower (PS) gives 110.32 kW for 150 PS. Then switch to kW to hp and type 100 for an electric car motor: it shows 134.1 hp, or 135.96 PS.
How Do You Use the Horsepower to kW Converter?
Pick a direction
Choose hp to kW, or kW to hp if your number is in kilowatts.
Choose the horsepower type
Pick mechanical hp, metric PS or electrical hp, then type the power.
Set decimal places
Use 0 or 1 for car specs, or more for engineering work.
Read the result
The big number is the answer, with watts, PS and mechanical hp below.
Frequently Asked Questions
How many kW is 1 horsepower?
One mechanical horsepower is 0.7457 kW, or 745.7 watts. One metric horsepower (PS) is 0.7355 kW, and one electrical horsepower is exactly 0.746 kW. Pick the type that matches your spec sheet.
How many horsepower is 1 kW?
One kilowatt is 1.341 mechanical horsepower, or 1.360 metric horsepower (PS). So a 100 kW electric motor is about 134 hp or 136 PS. Divide kW by 0.7457 for hp, or by 0.7355 for PS.
Is bhp the same as hp?
Brake horsepower uses the same unit as mechanical hp, 745.7 W. The difference is where it is measured: bhp is at the engine crankshaft, before losses in the gearbox and wheels, so power at the wheels is lower.
Why do European cars list PS and kW?
EU type approval papers give engine power in kW, the SI unit. Many makers also quote PS, metric horsepower, in adverts because buyers know it. 150 PS equals 110.32 kW.
How many hp is a 2.2 kW motor?
A 2.2 kW motor is about 2.95 mechanical hp, often sold as a 3 hp motor. Divide 2,200 W by 745.7 W to get 2.95 hp, or by 746 W for electrical hp, which also gives 2.95 hp.
What does horsepower mean in watts?
Horsepower is a unit of power, the rate of doing work. One mechanical horsepower is 745.7 joules of work per second, or 745.7 watts, a little more than a typical 700 W microwave draws.
Sources and Further Reading
- NIST Guide to the SI, Appendix B.9: factors for horsepower
- BIPM: The SI Brochure, the watt and derived units
- Wikipedia: Horsepower (definitions of mechanical, metric and electrical hp)
Related Tools
Last reviewed: October 2026