HP to kW Converter

Enter a power in mechanical horsepower to see kilowatts. This is the common US automotive horsepower, not metric PS.

How it works

Mechanical horsepower is defined as 550 foot-pounds per second, which is 745.6998715822702 watts. Dividing by 1000 gives kilowatts: multiply hp by 0.7456998716. 100 hp is about 74.57 kW. Metric horsepower (PS, Pferdestärke) is 735.49875 W — about 1.4% smaller — and is not used here.

Formula

kW = hp × 0.7456998715822702

Worked examples

100 hp → 74.5700 kW
1 hp → 0.7457 kW

Useful notes

Standard: mechanical (imperial) horsepower, 550 ft·lbf/s.
Not metric horsepower (PS) and not boiler horsepower.

FAQ

How many kilowatts is 1 horsepower?: About 0.7457 kW for mechanical horsepower (exactly 745.6998716 W).
Is this the same as metric HP?: No. Metric PS is 735.49875 W. A “100 PS” engine is about 73.55 kW, not 74.57 kW.
Do EV motors use horsepower?: They are usually quoted in kW. Convert kW to hp on the inverse page if you want a horsepower reading.

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