Converters
Power Converter
Pick a 'from' unit and a 'to' unit, enter a value, and the converter returns all common power units. Handles SI (W, kW, MW), imperial (mechanical hp), heating/cooling (BTU/h), and ft·lb/s.
Decimals are fine. Negative power is unusual but accepted. · e.g. 1
Internal base unit is the watt. Each conversion goes through watts, so accuracy is consistent across pairs.
Kilowatt → Horsepower
1.341022 hp
1 kW = 1.341022 hp
1 kW = 1,000 W; 1 MW = 1,000,000 W. 1 mechanical hp ≈ 745.7 W; 1 BTU/h ≈ 0.2931 W; 1 ft·lb/s ≈ 1.356 W. Mechanical horsepower is the standard "imperial" hp; metric (PS) and electrical hp are slightly different.
Examples
1 kW
≈ 1.341 mechanical hp; 3,412 BTU/h
100 mechanical hp
= 74,570 W; 254,433 BTU/h
24,000 BTU/h
≈ 7,033 W; 9.43 hp (cooling)
1 ft·lb/s
≈ 1.356 W
How it works
Each power unit is defined by its size in watts. The converter multiplies the input by the "from" factor (in watts), then divides by the "to" factor.
SI scale · 1 kW = 1,000 W; 1 MW = 1,000,000 W
Imperial · 1 mech. hp ≈ 745.7 W; 1 ft·lb/s ≈ 1.356 W
HVAC · 1 BTU/h ≈ 0.293 W
Related calculators
- Energy converter for the related total-energy units (J, kJ, cal, kcal, Wh, kWh, BTU).
- Calories burned calculator for activity-level energy expenditure (a power-times-time math).
- Scientific calculator for arithmetic checks of the result.
- All converters.
Frequently asked questions
Power is the rate of energy transfer (energy per unit time). The SI unit is the watt: 1 watt = 1 joule per second. Higher units (kilowatt, megawatt) scale by 1,000 each step.
Mechanical horsepower (the most common imperial hp) is 745.699872 watts. Metric horsepower (PS) is slightly different at 735.499 watts. This converter uses mechanical hp.
BTU per hour is the standard rating unit for heating and air conditioning equipment in the US. A 24,000 BTU/h air conditioner is also rated at about 7,033 watts or 2 tons of cooling.
Foot-pound per second is a rarely-used imperial power unit (work done per second). 1 ft·lb/s ≈ 1.356 watts. James Watt originally defined horsepower as 550 ft·lb/s.
Almost. Electrical hp is defined as exactly 746 watts, used for motors. Mechanical hp is 745.7 watts. The difference is tiny; in most everyday use the two are interchangeable.
Related calculators
Converters
Length Converter
Convert between millimeters, centimeters, meters, kilometers, inches, feet, yards, miles, and nautical miles.
Converters
Weight Converter
Convert weight and mass units: milligram, gram, kilogram, metric tonne, ounce, pound, stone, US ton, and imperial ton.
Converters
Temperature Converter
Convert between Fahrenheit, Celsius, Kelvin, and Rankine using exact formulas. Flags impossible values below absolute zero.