Power Converter
Convert between watts, kilowatts, horsepower, BTU per hour and more. Handy for comparing engine ratings, sizing generators or reading appliance labels.
To convert a total rather than a rate, use the Energy Converter; for vehicle figures, see Fuel Consumption.
How to use the Power Converter
- 1 Enter the power value you want to convert.
- 2 Choose the source unit — watt, kilowatt, megawatt, horsepower or BTU per hour.
- 3 Read the equivalent across the other units.
- 4 Swap to convert in the opposite direction.
How It Works
Every unit is defined as a multiple of the watt. Your value is converted to watts and then distributed across all the other units at the precision you choose.
- Watt, kilowatt and megawatt
- Mechanical and metric horsepower
- BTU/hour and refrigeration tons
- Foot-pounds per second
- Full conversion table
Frequently asked questions
Why do two horsepower figures not match?
Because there is more than one definition. Mechanical horsepower is 745.7 W, metric horsepower (PS) is 735.5 W, and boiler and electric horsepower differ again. Car specifications usually mean metric PS in Europe and mechanical hp in the US, so the same engine can appear to have two different ratings.
Why is the watt the standard unit?
It is the SI unit — one joule per second — so it plugs directly into electrical formulas. Horsepower is a historical comparison to draft animals and has no place in physics, which is why it survives only in marketing and tradition.
What does BTU per hour mean on an air conditioner?
It is a cooling capacity, not an electrical draw. A "12,000 BTU" unit removes about 3.5 kW of heat, roughly matching a 1-ton system. Its electricity consumption is a separate figure, usually around 1 kW, which is why capacity and running cost are not the same number.
Related Unit & Data Converters
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