Power Converter – kW, HP, Watts & BTU/h

Convert watts, kilowatts and horsepower

Power describes how quickly energy is transferred or work is done. Enter a rating in watts, kilowatts, megawatts, horsepower, BTU per hour or refrigeration tons and the converter updates the selected target unit. The same calculation works in reverse, so it can compare motor nameplates, engine specifications, electrical loads and cooling-system capacities without a separate formula.

Mechanical horsepower and metric horsepower

This converter labels the two horsepower definitions separately because they are close but not interchangeable. One mechanical horsepower is approximately 745.699871582 watts and is commonly written hp. One metric horsepower is exactly 735.49875 watts and is also known as Pferdestärke or PS. A specification that says only “horsepower” should be checked for its market and standard before converting.

How do you convert kilowatts to mechanical horsepower?

Multiply kilowatts by approximately 1.34102209. For example, 100 kW is approximately 134.102209 mechanical hp. To reverse the calculation, multiply mechanical horsepower by approximately 0.745699872 to get kilowatts. Use the dedicated kW to hp converter for a table and worked examples.

Watts, kilowatts and megawatts

The SI steps are decimal: 1 kilowatt is exactly 1,000 watts and 1 megawatt is exactly 1,000 kilowatts or 1,000,000 watts. These units express power, not energy consumed over time. A kilowatt-hour is energy, so convert it with the energy converter instead of treating kW and kWh as equivalents.

BTU per hour and refrigeration tons

Heating and cooling equipment often states capacity in British thermal units per hour. Using the International Table BTU, 1 BTU/h is approximately 0.2930710702 watts. One refrigeration ton is defined here as 12,000 BTU/h, approximately 3.516852842 kW. Refrigeration ton is a cooling-rate unit; it is not a unit of mass.

Convert cooling capacity without losing the time basis

Use watts to BTU per hour when comparing an electrical or heat-transfer rate, and BTU per hour to refrigeration tons for rated cooling capacity. BTU without “per hour” is energy rather than power. Equipment input power and cooling output capacity can also differ because a heat pump or air conditioner moves heat; this converter changes units only and does not calculate efficiency, COP or electrical cost.

Definitions, precision and practical limits

Linear conversions use watts as a shared base and retain the stored factors before display rounding. Published equipment ratings may already be rounded and real output can vary with voltage, temperature, load and operating conditions. Use the result for unit comparison, then follow the manufacturer’s rated-data and safety guidance for sizing, wiring or engineering decisions. Values are calculated locally in the browser and are not submitted with the conversion.