How to use the power converter
- Type a value in either box. Decimals with a comma or a point both work.
- Choose the units on each side, or press the arrows to swap them.
- The table below shows the value in every unit at once. Click a row to convert to that unit.
About power units
Power is energy per unit of time: one watt is one joule per second. Engines and motors are rated in kilowatts in most of the world, while horsepower is still common for cars in the US and UK.
There is more than one horsepower. Mechanical horsepower is 550 foot-pounds per second, 745.70 W. Metric horsepower, written PS in German, ch in French and CV in Italian and Spanish, is 735.49875 W, about 1.4% less. So 1 kW is 1.34102 hp but 1.35962 PS, and a car rated at 150 PS makes 147.95 hp.
Air conditioners are often rated in BTU per hour, and a ton of refrigeration is 12,000 BTU/h, or 3.51685 kW.
Popular power conversions
Power units
| Unit | Symbol | Definition |
|---|---|---|
| Watts | W | The base unit |
| Kilowatts | kW | 1 kW = 1,000 W |
| Megawatts | MW | 1 MW = 1,000,000 W |
| Gigawatts | GW | 1 GW = 1,000,000,000 W |
| Horsepower | hp | 1 hp = 745.6998716 W |
| Metric horsepower | PS | 1 PS = 735.49875 W |
| BTU per hour | BTU/h | 1 BTU/h = 0.2930710702 W |
| Tons of refrigeration | TR | 1 TR = 3,516.852842 W |
Converting something else? The unit converter covers every kind of unit in one place.