About this tool
Convert a power value between eight units, entirely in your browser with no upload. Set the From and To units, type a number, and the result updates as you go; ⇄ swaps the units.
Power is measured against the base unit watt (W): the value is multiplied by the From factor to get watts and divided by the To factor. Note there are two horsepower definitions — mechanical (1 hp = 745.699872 W) and metric/PS (1 PS = 735.49875 W) — which differ by about 1.4%, so choose the right one.
Useful for motors, engines, HVAC and appliances. For example 1 mechanical horsepower ≈ 0.7457 kW, and 1 kW ≈ 3412.14 BTU/hour.
Frequently asked questions
Which base unit does it use?
The watt (W). Each unit has an exact factor to watts; conversions are value × from-factor ÷ to-factor.
What is the difference between the two horsepower units?
Mechanical (imperial) horsepower is 745.699872 W, while metric horsepower (PS) is 735.49875 W — about 1.4% smaller.
How many kW is 1 horsepower?
One mechanical horsepower is about 0.7457 kW; one metric PS is about 0.7355 kW.
Does anything leave my device?
No. The calculation is pure JavaScript running locally; no data is uploaded or saved.