Power Converter

Power Converter

Convert power between watts, kilowatts, megawatts, gigawatts, milliwatts, mechanical, metric, and electrical horsepower, BTU per hour, kilocalories per hour, foot-pounds per second, tons of refrigeration, and ergs per second. Enter one value and compare engine ratings, heater outputs, and air conditioner capacities side by side.

Horsepower comes in three flavors

A German car brochure listing 150 PS and an American one listing 148 hp describe almost the same engine. Converting both to kilowatts – the official EU unit – removes the confusion.

Heating and cooling

HVAC equipment is often rated in BTU per hour or in tons of refrigeration. One ton equals 12,000 BTU/h, which is about 3.517 kW. A 9,000 BTU/h split air conditioner delivers roughly 2.64 kW of cooling – note that this is thermal output, not the electrical power it draws.

Worked example

Your electric car has a 150 kW motor. Select kilowatt, enter 150, and the table shows about 201.2 hp and 203.9 PS. For solar panels, 400 W equals 0.4 kW, and a 10 kW home system is 10,000 W.

Power vs. energy

Power is a rate – energy per unit of time. A 2 kW kettle running for half an hour uses 1 kWh of energy. To convert kilowatt-hours, joules, or calories, use the Energy Converter; to relate power to current at a known voltage, see the Electric Current Converter.