How to use the kilowatt to horsepower converter
- Enter the power value you want to convert.
- Choose the unit it is in under From and the unit you want under To.
- Read the answer in the headline. The same power is shown in every unit in the table below, so you can see mechanical, metric and electric horsepower side by side.
- Use Copy, Print or export the CSV to keep the table.
Formula
watts = value x watts per unit of the From unit
result = watts / watts per unit of the To unit
1 mechanical hp = 550 ft lbf/s = 745.69987 W
1 metric hp (PS) = 75 kgf m/s = 735.49875 W
1 electric hp = 746 W
A foot-pound force is 1.3558179 W per ft lbf/s, built from the exact definitions of the foot, pound and standard gravity. A BTU per hour uses the International Table BTU, 1,055.05585262 J, divided by 3,600 seconds. Results show up to eight significant digits.
100 kW in horsepower
100 kW is 100,000 W. Divided by 745.69987 W per mechanical horsepower, that is 134.10221 hp. As metric horsepower (PS) it is 100,000 / 735.49875 = 135.96216, and as electric horsepower it is 100,000 / 746 = 134.04826.
In the other direction, one mechanical horsepower is 745.69987 W, or 0.74570 kW. The same 100 kW is 341,214.16 BTU per hour.
Three kinds of horsepower
The word horsepower covers several different units. Mechanical horsepower, used for engines in the United States, is 550 foot-pounds of force per second. Metric horsepower, shown as PS or CV on many European and Asian specifications, is slightly smaller. Electric horsepower, used for motors, is a round 746 watts. The gap between them is about one percent, which is small but enough to matter when you compare two spec sheets.
When a rating does not say which kind it uses, assume the difference and check the maker. A rating in kilowatts is unambiguous.
Rated power versus delivered power
This page converts units. It does not tell you how much power reaches the wheels or the shaft. Engine ratings may be measured at the crankshaft, and drivetrain losses lower what the wheels receive. Heating and cooling equipment are often rated in BTU per hour, which this converter also handles.
For related work, see the horsepower from torque calculator, the power to weight ratio calculator, the BTU calculator and the kilowatt to amps calculator.
Assumptions and limits
- Power must be zero or more, up to 1e15. The page converts units and does not model losses.
- Mechanical, metric and electric horsepower are kept separate. The page never treats them as one unit.
- BTU per hour is the International Table BTU. Other BTU definitions differ slightly.
- Nothing is stored or uploaded.
Frequently asked questions
How many horsepower is 1 kW?
One kilowatt is about 1.341 mechanical horsepower, 1.360 metric horsepower or 1.340 electric horsepower. The difference comes from the three definitions of horsepower, which this page keeps apart.
How do I convert hp to kW?
Multiply mechanical horsepower by 0.74570 to get kilowatts. For metric horsepower use 0.73550, and for electric horsepower use 0.746. Choose the units above and the page does it for you.
Why are there different kinds of horsepower?
Horsepower was defined separately in different places and for different uses, so the units differ by about one percent. The page names each kind so you can see which one a rating uses.
Is a BTU per hour a unit of power?
Yes. A BTU is an amount of energy, and per hour makes it a rate of energy, which is power. One BTU per hour is about 0.293 watts, and heating and cooling equipment is often rated in it.