Power Converter
Convert power between watts, kilowatts, horsepower and BTU per hour - useful for car engines, motors and heating or cooling specs.
About the Power Converter
This tool converts a power rating between watts, kilowatts, megawatts, horsepower and BTU per hour. Power is the rate at which energy is used or produced, so these units describe engines, electric motors, appliances and heating or cooling equipment.
How to use it
- Enter the rating you know into its field, for example an engine in horsepower.
- Read the equivalent in kilowatts or BTU per hour.
- Convert in either direction when a spec sheet uses an unfamiliar unit.
A frequent use is comparing a car engine quoted in horsepower against one in kilowatts, where 1 metric horsepower is about 0.7355 kW (so 100 hp is roughly 73.5 kW). Heating and air-conditioning units are often rated in BTU per hour, and 1 kW equals about 3412 BTU/h. Be aware there are slightly different horsepower definitions (metric versus mechanical); this tool uses the metric horsepower. The converter runs in your browser and uploads nothing.
Frequently asked questions
How many watts are in one horsepower?
One metric horsepower equals about 735.5 watts, while the mechanical (imperial) horsepower is about 745.7 watts. This converter uses the metric horsepower.
How do I convert kilowatts to horsepower?
Divide kilowatts by 0.7355 for metric horsepower. So a 73.5 kW motor is about 100 hp.
What is the difference between power and energy?
Power is the rate of energy use, measured in watts, while energy is the total amount used over time, measured in joules or kilowatt-hours. A 1 kW heater running for 1 hour uses 1 kWh of energy.
How many BTU per hour is 1 kilowatt?
One kilowatt equals about 3412 BTU per hour. This conversion is handy when comparing air-conditioner ratings given in BTU/h to electrical power in kW.