Converters
Power Converter
Convert W, kW, MW, hp, PS, BTU/h, and kcal/h.
About This Tool
Convert rates of energy transfer used in electrical equipment, engines, heating and cooling, and engineering specifications. Enter one power value and compare watts, kilowatts, megawatts, mechanical horsepower, metric horsepower, BTU per hour, and kilocalories per hour. The calculation runs locally in your browser.
How To Use It
- Enter the power value you want to convert.
- Choose its current unit, such as kW, W, hp, or BTU/h.
- Choose the destination unit and read the converted result.
- Use the comparison table to see the same rate of energy transfer in every supported unit.
Examples
1 kW to watts
One kilowatt equals exactly 1,000 watts.
1 mechanical hp to watts
This converter uses 1 mechanical horsepower = 745.6998715822702 watts.
BTU/h to watts
Using the International Table BTU convention, about 3,412.1416 BTU/h equals 1,000 watts.
Useful Notes
Power is a rate, while energy is an amount
A watt is one joule per second, so power describes how quickly energy is transferred or used. This is different from energy units such as joules and kilowatt-hours. Use the Energy Converter when you need to convert an amount of energy rather than a rate.
Mechanical and metric horsepower are different
Horsepower is not one universal unit. This tool labels mechanical horsepower as hp and uses 745.6998715822702 W per hp. Metric horsepower, commonly written PS, is 735.49875 W. Keeping them separate prevents a small but meaningful conversion error.
BTU per hour convention
BTU/h is a power unit often used for heating and cooling. This converter derives it from the International Table BTU value of 1,055.05585262 J, divided by 3,600 seconds per hour.
Kilocalories per hour convention
The kcal/h conversion uses the thermochemical kilocalorie: 4,184 J per kcal. Dividing by 3,600 seconds per hour gives the equivalent power in watts.
Signed values
Negative values are preserved because engineering calculations can use signed power to represent direction of transfer or generation versus consumption. The converter changes units only and does not assign a physical interpretation to the sign.
FAQ
How many watts are in 1 kilowatt?
One kilowatt equals exactly 1,000 watts.
How many watts are in 1 horsepower?
For mechanical horsepower, this tool uses approximately 745.6999 watts per hp. Metric horsepower is different at 735.49875 watts per PS.
Is kW the same as kWh?
No. kW measures power, a rate of energy transfer. kWh measures energy accumulated over time.
Why might horsepower conversions differ elsewhere?
Different horsepower definitions exist. This tool explicitly separates mechanical horsepower (hp) from metric horsepower (PS), so compare the unit convention used by the source you are checking.
Related Tools
Energy Converter
Convert J, kJ, MJ, Wh, kWh, cal, kcal, and BTU.
Pressure Converter
Convert Pa, kPa, MPa, bar, psi, atm, mmHg, and Torr.
Temperature Converter
PopularConvert Celsius, Fahrenheit, and Kelvin temperatures.
Basic Calculator
PopularA simple arithmetic calculator for quick results.