Power Converter
Convert power between watts, kilowatts, megawatts, mechanical horsepower, metric PS and BTU per hour — free, instant and private. Every conversion is calculated in your browser.
How to use the power converter
- Enter a value. Type the amount of power you want to convert into the Value box — for example, 150 to convert 150 horsepower.
- Choose your units. Pick the unit to convert from and the unit to convert to, and use the ⇄ button to swap them instantly.
- Read the result. The converted power appears at once, along with a table showing the same value in every other power unit.
About this tool
This free power converter links the units used for engines, appliances, climate control and electricity generation. Car makers quote engine output in horsepower, metric PS or kilowatts; household appliances are rated in watts and kilowatts; air conditioners are sized in BTU per hour; and power stations are measured in megawatts. The watt is the SI base unit, and each other unit is defined against it: mechanical horsepower is about 745.70 W, metric horsepower (PS) is about 735.50 W, and 1 BTU/h is roughly 0.293 W.
Power is the rate at which energy is used or produced, so it is easy to confuse with energy itself — a 2 kW heater running for one hour consumes 2 kWh of energy. This converter keeps you in power units and shows the whole table at a glance. All calculations run locally in your browser with JavaScript, so nothing you type is uploaded, and the tool keeps working offline once loaded.
Frequently asked questions
How many watts are in one horsepower?
One mechanical (imperial) horsepower is about 745.70 watts, so a 100 hp engine is roughly 74.6 kW. Metric horsepower, written PS or CV, is slightly less at about 735.50 watts.
What is the difference between hp and PS?
Mechanical horsepower (hp) is the imperial unit used in the UK and US, while PS (Pferdestärke) is the metric horsepower common in Europe and Japan. One PS equals about 0.9863 hp, so metric figures read slightly higher.
How do I convert kilowatts to horsepower?
Multiply kilowatts by about 1.341 to get mechanical horsepower. For example, 100 kW is roughly 134 hp. To convert horsepower to kilowatts, multiply by 0.7457.
Why are air conditioners rated in BTU per hour?
BTU/h expresses how much heat an air conditioner can move each hour, which is a power figure. Around 3,412 BTU/h equals 1 kilowatt, so a 12,000 BTU/h unit provides about 3.5 kW of cooling.