Power Converter
Convert power between watts, kilowatts, horsepower (mechanical, metric and electric), BTU per hour and kilocalories per hour.
Change the values and press Calculate to work out your own figures.
Enter a power, choose its unit and the unit you want. The answer is exact until it is shown, and the same value appears in every other unit.
Show the working
- 1 hp = 0.745699871582 kW
- 1 × 0.745699871582 = 0.745699871582 kW
How to use it
Type a power, choose the unit it is in and the unit you want, then press Calculate. You can type decimals, fractions such as 3/8, mixed numbers such as 1 1/2, very large or small numbers such as 2.5e6, and simple sums such as 2*3. Swap exchanges the two units.
The answer is worked out with exact fractions and only rounded for display, to 12 significant figures. Below it you get the same value in every other unit on the list, and Show the working gives the factor that was used.
Key definitions
1 hp = 550 ft·lbf/s ≈ 745.7 W 1 PS ≈ 735.5 W 1 kW = 1,000 W
Three horsepowers
Mechanical horsepower (hp, 745.7 W) is used for US and UK cars and engines; metric horsepower (PS or CV, 735.5 W) for European cars; electric horsepower (746 W) for electric motors. A 200 PS car has about 197 hp.
Air conditioners
Air conditioners are often rated in BTU per hour: 12,000 BTU/h is about 3.5 kW of cooling, sometimes called one ton of refrigeration.
Questions
How many watts is one horsepower?
About 745.7 W for mechanical horsepower, 735.5 W for metric horsepower.
How many kW is a 12,000 BTU air conditioner?
About 3.5 kW of cooling.
Formulas
result = (value × f(from) + o(from) − o(to)) ÷ f(to)
Sources
Limitations
- Only the units listed are supported here; other power units arrive with later M4 slices.