How many watts is one horsepower?

One mechanical (imperial) horsepower equals 745.6999 watts, defined as 550 foot-pounds-force per second. So a 100 hp engine is about 74,570 W or 74.57 kW.

How do I convert watts back to horsepower?

Divide the watts by 745.6999. For example, 10,000 W / 745.6999 = 13.41 hp. This converter does both directions.

Which horsepower does this use?

It uses mechanical (imperial) horsepower, the standard for engines and motors in the US and UK. Metric horsepower (PS) is slightly different at about 735.5 W and is not used here.

How do I get kilowatts from horsepower?

Convert to watts then divide by 1000, which works out to about 0.7457 kW per hp. So 150 hp is roughly 111.85 kW.

What is the difference between mechanical and metric horsepower?

Mechanical (imperial) horsepower is 745.7 W, based on 550 ft-lbf/s. Metric horsepower (PS, cheval-vapeur) is 735.5 W, based on 75 kgf-m/s. Car specs in Europe often quote PS, which is about 1.4% smaller.

Is my data sent anywhere?

No — the conversion runs entirely in your browser and nothing is uploaded to any server.

Horsepower to Watts Converter

Horsepower to watts — the exact conversion

One mechanical horsepower equals 745.6999 watts. This converter turns horsepower (hp) into watts (W) and back, using the precise definition of 745.69987158 W per horsepower. Mechanical horsepower is the figure quoted for car engines, pumps and motors in the US and UK.

How it works

Mechanical horsepower is defined as 550 foot-pounds-force per second, which equals exactly 745.69987158 watts. The converter multiplies horsepower by this factor to get watts, or divides watts by it to get horsepower. To reach kilowatts, divide the watt result by 1000. The chosen direction and your value are combined instantly with no rounding beyond the display.

Example

Convert a 200 hp engine to watts:

200 × 745.6999 = 149,140 W = 149.14 kW

Going back, a 3 kW electric motor is 3000 / 745.6999 = 4.02 hp.

Horsepower (hp)	Watts (W)	Kilowatts (kW)
1	745.70	0.746
100	74,570	74.57
200	149,140	149.14
500	372,850	372.85

Pick a direction, type your number, and the answer updates instantly — all in your browser, with no data leaving your device.