Power Unit Converter
Convert power between watts, kilowatts, megawatts, mechanical and metric horsepower, and BTU per hour.
- Converted value
- 0.7457
How it works
Every unit converts to watts first using its exact defined value, then from watts to the target unit — the same through-a-common-base-unit approach as this site's other unit-*.ts converters. Mechanical (imperial) horsepower is defined as 550 foot-pounds-force per second, which works out to 745.699872 W. Metric horsepower (PS, or CV) is defined as 75 kilogram-force-meters per second — since a kilogram-force is fixed by standard gravity (9.80665 m/s²), that's exactly 735.49875 W.
BTU per hour uses the same International Table BTU already behind this site's energy converter (1,055.05585262 J) divided by the 3,600 seconds in an hour, since power is just energy per unit time.
These are all fixed, internationally defined conversion factors, not measurements that could go out of date — a horsepower has meant the same number of watts since it was formally defined, the same reasoning this site's other unit-*.ts converters rely on.
FAQ
Why are there two different 'horsepower' values?
Mechanical (sometimes called 'imperial' or 'hydraulic') horsepower is the older US/UK definition, common in North American engine and pump ratings. Metric horsepower (PS in German, CV in French/Spanish/Italian) is the definition used across most of continental Europe and Asia for vehicle specs. They're close — about 1.4% apart — but not identical, so converting between a US-spec engine's hp rating and a European-spec car's PS rating needs the right constant, not a straight 1:1 read.
Is a kilowatt-hour the same as a kilowatt?
No — a kilowatt is a rate of power (energy per second), while a kilowatt-hour is a quantity of energy (a kilowatt sustained for an hour). This calculator converts power units only; for energy units, including kWh, see this site's energy converter instead.