What is power converter?
A power converter changes the rate of energy use between units such as watts, kilowatts and horsepower. It is used for engines, appliances, solar panels and heating equipment.
Mechanical horsepower is 745.7 watts, while metric horsepower is 735.5 watts.
How to use the power converter
- Enter the value.
- Choose the unit you have and the unit you want.
- Read the result and the table of all units.
How the power converter works
Each value is converted to watts using exact factors. One kilowatt is 1,000 watts, one mechanical horsepower is 745.69987 watts and one BTU per hour is 0.29307 watts. The result is divided by the target factor.
Worked example
Common uses of the power converter
- Comparing car engines.
- Sizing air conditioners and heaters.
- Solar panel planning.
- Appliance wattage checks.
- Physics homework.
Tips and common mistakes
Car makers outside the United States often quote metric horsepower or kilowatts.
Use the table to compare many units at once.
Background: what to know before you rely on it
Power is the rate at which work is done or energy is used. The watt is one joule per second. James Watt introduced horsepower in the 1700s to sell steam engines by comparing them with draft horses. Because several definitions of horsepower exist, quoting the standard used avoids confusion. Modern vehicles and appliances increasingly use kilowatts, which fit neatly with electricity bills.
Private, free and fast
This tool runs entirely in your browser. What you type or choose is not uploaded to a server and is not saved after you close the page, which keeps it fast and private. It is free to use as often as you like. See more in all converters, or browse the full list of tools.
Frequently asked questions
How many watts are in a horsepower?
745.7 for mechanical horsepower.
What is the difference between mechanical and metric horsepower?
About 1.4 percent.
How many kW is 1 hp?
About 0.7457 kW.
What does BTU per hour measure?
Heating and cooling capacity.
Related tools
Energy Converter
Enter an amount of energy, choose the units and read the exact result. A table shows every other energy...
ConvertersPressure Converter
Enter a pressure, choose the units and read the exact result. A table shows the value in every other...
ConvertersUnit Converter
Pick a category, choose the unit you have and the unit you want, then enter a value. The converter also...
ConvertersSpeed Converter
Enter a speed, choose the units and read the result. A table shows the value in km/h, mph, m/s and...
ConvertersTemperature Converter
To convert Celsius to Fahrenheit, multiply by 9/5 and add 32. To convert Fahrenheit to Celsius, subtract...
ConvertersRoman Numeral Converter
Roman numerals use the letters I, V, X, L, C, D and M for 1, 5, 10, 50, 100, 500 and 1000. Enter a...
Results are for information and education. For legal, financial, medical or security decisions, check with a qualified professional. Check critical conversions with an official source.