Power Converter
Convert between watts, kilowatts, mechanical and metric horsepower, and BTU per hour.
Processing: This tool runs entirely in your browser. Your input and any file you open stay on your device — nothing is uploaded to a server.
How to use the power converter
- Type the amount you want to convert.
- Choose the unit you have and the unit you want.
- Read the result, or use the table showing all 6 units at once.
About this tool
Power is energy per unit of time — a watt is one joule per second — so a power figure says how fast something delivers or consumes energy, not how much in total.
There are two horsepowers in common use and they differ by about 1.4%. Mechanical horsepower (745.7 W) is standard in the US and UK; metric horsepower, written PS or CV (735.5 W), is used across much of Europe. Car specifications quote whichever their market expects, which is why the same engine can be listed with two different figures.
Common uses
- Comparing car engine outputs quoted in kW, hp and PS.
- Converting an appliance rating for a specification.
- Reading an air-conditioning capacity given in BTU per hour.
Frequently asked questions
- How many watts is one horsepower?
- 745.7 W for mechanical horsepower, or 735.5 W for metric horsepower (PS). Both are offered.
- What is the difference between kW and kWh?
- Kilowatts measure rate, kilowatt hours measure quantity. A 2 kW heater running for 3 hours uses 6 kWh.
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