Watts, kilowatts, mechanical hp, metric hp (PS) and electrical hp

Watt to Horsepower Calculator

Horsepower is not one unit but three. Choose watts or kilowatts, and this calculator returns mechanical hp, metric hp (PS) and electrical hp together, or goes in reverse from horsepower to watts.

Result
Mechanical horsepower
hp
Metric horsepower
PS
Electrical horsepower
1.340 hp(E)
Input
1,000 W
Kilowatts
1.000 kW

The three definitions of horsepower

UnitWatts per unitUsed for
Mechanical hp (hp, bhp)745.6999US and UK car power
Metric hp (PS, CV, cv)735.49875Europe, Japan
Electrical hp746Motors

So 1 kW is about 1.341 mechanical hp or 1.360 PS. A 100 kW engine is 134 hp or 136 PS.

Formulas

hp = watts ÷ 745.7 and watts = hp × 745.7. For kilowatts to horsepower multiply by 1.341. For hp to kW multiply by 0.7457.

Quick kW-to-hp table

kWMechanical hpPS
506768
75101102
100134136
150201204
200268272
300402408
400536544
500671680

Frequently asked questions

How many watts are in a horsepower?

One mechanical horsepower is 745.7 watts; one metric horsepower (PS) is 735.5 watts.

How many horsepower is 1000 watts?

1,000 W is 1.341 mechanical horsepower.

Why is PS different from hp?

PS is defined as lifting 75 kg one metre in a second, which gives 735.5 W, while mechanical hp is based on 550 ft·lbf/s.

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