7 units · 42 conversions

Power Converter

Convert watts, kilowatts, horsepower and BTU per hour.

Popular Power conversions

Watts to Kilowatts W → kW Watts to Megawatts W → MW Watts to Horsepower W → hp Watts to Metric Horsepower W → PS Watts to BTU per Hour W → BTU/h Watts to Foot-pounds/min W → ft·lb/min Kilowatts to Watts kW → W Kilowatts to Megawatts kW → MW Kilowatts to Horsepower kW → hp Kilowatts to Metric Horsepower kW → PS Kilowatts to BTU per Hour kW → BTU/h Kilowatts to Foot-pounds/min kW → ft·lb/min Megawatts to Watts MW → W Megawatts to Kilowatts MW → kW Megawatts to Horsepower MW → hp Megawatts to Metric Horsepower MW → PS Megawatts to BTU per Hour MW → BTU/h Megawatts to Foot-pounds/min MW → ft·lb/min Horsepower to Watts hp → W Horsepower to Kilowatts hp → kW Horsepower to Megawatts hp → MW Horsepower to Metric Horsepower hp → PS Horsepower to BTU per Hour hp → BTU/h Horsepower to Foot-pounds/min hp → ft·lb/min Metric Horsepower to Watts PS → W Metric Horsepower to Kilowatts PS → kW Metric Horsepower to Megawatts PS → MW Metric Horsepower to Horsepower PS → hp Metric Horsepower to BTU per Hour PS → BTU/h Metric Horsepower to Foot-pounds/min PS → ft·lb/min

All Power conversions (42)

All Power units

Watts W Kilowatts kW Megawatts MW Horsepower hp Metric Horsepower PS BTU per Hour BTU/h Foot-pounds/min ft·lb/min

About Power

Power covers seven units and it is the category where cars, electricity bills and air conditioning all meet. Watts, kilowatts and megawatts are the SI units, used for appliances, electric motors, solar panels and generating stations. Horsepower is the traditional unit for engines. Metric horsepower, often written PS, is the European variant and is what most car specs outside the US actually quote. BTU per hour rates heating and cooling equipment. Foot-pounds per minute appears in older mechanical engineering. Visitors arrive to compare a car quoted in one unit against one quoted in another, size a generator or a solar array, work out what an air conditioner will draw, or read a motor plate. The pages used most are kilowatts to horsepower, horsepower to kilowatts, watts to BTU per hour and horsepower to metric horsepower.

Two things are worth knowing here. The first is that there is more than one horsepower. The mechanical horsepower used in the English-speaking world and the metric horsepower used across continental Europe and in Japanese and German car specs are close in size but not identical. That is why the same car is often advertised with two slightly different power figures in different markets, and why this hub lists them as separate units rather than pretending they are one. If you are comparing cars across markets, check which one the spec means. The second is that power is not energy. Power is a rate: how fast energy is used or produced at a given moment. Energy is the total accumulated over time. A heater rated in kilowatts tells you how hard it works; the kilowatt-hours on your bill tell you how much it consumed. Mixing them up is the most common conceptual error people bring to this hub. If you want totals and running costs rather than rates, use the energy converter.

Each pair page shows the formula it applied, works through an example, and lists a reference table of common ratings. The pages are free, need no sign-up, and every calculation runs in your own browser, so nothing you type goes to a server.

Frequently asked questions

What is the difference between horsepower and metric horsepower?

They are two similar but distinct units. Mechanical horsepower is standard in the US and UK, while metric horsepower, usually written PS, is standard across continental Europe and in many Japanese and German specifications. They are close in size but not equal, which is why the same car is often advertised with slightly different power figures in different markets. This hub lists both separately so you can convert between them explicitly.

Is power the same as energy?

No. Power is the rate at which energy is used or produced, and energy is the total amount over time. A kettle rated at a certain number of watts tells you how fast it draws energy; the kilowatt-hours on your bill tell you how much it used overall. Watts, kilowatts and horsepower are all rates and belong here, while joules and kilowatt-hours are totals and belong in the energy converter.

Why are air conditioners rated in BTU per hour?

Because BTU is the traditional heating and cooling unit and the industry has kept it, particularly in the US and UK. BTU per hour is the rate version of it, which makes it a power rating just like watts. Converting to watts or kilowatts is the easiest way to compare an imported unit against a metric spec, or to work out roughly what the equipment will draw from the supply.

Can I convert kilowatts to kilowatt-hours here?

Not directly, because they measure different things. Kilowatts are a rate and kilowatt-hours are a total, so getting from one to the other needs a duration as well as a conversion. A device drawing one kilowatt for one hour uses one kilowatt-hour. Convert the power figure here, then use the energy converter for the total once you know how long it runs.

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