How to convert horsepower to kilowatts
To convert a measurement in horsepower to kilowatts, multiply the value by 0.745699871582. The conversion factor comes from the relationship between both units and the watt.
For example, to convert 5 hp to kilowatts: 5 × 0.745699871582 = 3.728499 kW.
What is a horsepower?
Mechanical horsepower (hp) is a unit of power equal to about 745.7 watts, originally defined to compare engine output to the work of draft horses. James Watt coined horsepower in the 1780s to market his steam engines against the horses they replaced. Mechanical horsepower remains the dominant unit for engine power in the United States.
Common uses of horsepower include: Car and motorcycle engine ratings (US); Lawn mowers and power tools; Marine and outboard motors; Comparing engine performance.
What is a kilowatt?
A kilowatt equals 1,000 watts and is the standard unit for the power of motors, heaters, and electric vehicles. As electrical machinery grew more powerful, the kilowatt became the practical unit for rating engines and appliances, and it is now the metric counterpart to horsepower in automotive specifications.
Common uses of kilowatts include: Electric vehicle motor power; Home appliance and heater ratings; Car engine output (metric); Solar array and generator capacity.
When you need to convert horsepower to kilowatts
US engine ratings in horsepower often need converting to kilowatts for metric paperwork, insurance, or comparison with European vehicles. A 150 hp sedan is roughly 112 kW, which is the figure that appears on a European registration document.
Horsepower to kilowatts worked examples
Here are some common values converted:
1 hp = 0.745699871582 kW 5 hp = 3.728499 kW 10 hp = 7.456999 kW 50 hp = 37.284994 kW 100 hp = 74.569987 kW
Frequently asked questions
How many kilowatts are in one horsepower?
One horsepower (hp) equals 0.745699871582 kilowatts (kW). Multiply any value in horsepower by 0.745699871582 to convert to kilowatts.
How do I convert horsepower to kilowatts?
Multiply the value in horsepower by 0.745699871582. For example, 5 hp × 0.745699871582 = 3.728499 kW.
How do I convert kilowatts to horsepower?
Multiply the value in kilowatts by 1.341022, or divide by 0.745699871582. Use the swap button on the converter above to reverse the direction.
Is the horsepower to kilowatt conversion exact?
Mechanical horsepower is defined as exactly 745.7 W and metric horsepower as 735.49875 W. SI conversions are exact.
What is the formula for horsepower to kilowatts?
The formula is: kW = hp × 0.745699871582. This comes from the definition of both units relative to the watt.