Horsepower to Kilowatts
Type a value in either box to convert between horsepower and kilowatts. The factor is 0.7457.
| Horsepower | Kilowatts |
|---|---|
| 1 hp | 0.7457 kW |
| 2 hp | 1.4914 kW |
| 3 hp | 2.2371 kW |
| 5 hp | 3.728499 kW |
| 10 hp | 7.456999 kW |
| 25 hp | 18.642497 kW |
| 50 hp | 37.284994 kW |
| 100 hp | 74.569987 kW |
How to use
- Enter a value in the Horsepower field.
- The Kilowatts figure appears immediately — no button to press.
- Typing in the Kilowatts field converts back to Horsepower the same way.
- Use the reference table for the values that come up most often.
Horsepower to Kilowatts formula
Converting horsepower to kilowatts is a single multiplication by 0.745699872.
kW = hp × 0.745699872
Why this factor: the horsepower and the kilowatt are both defined against the watt, so dividing one definition by the other gives 0.745699872 directly. Both definitions are set out in full below.
To go the other way, divide by 0.745699872 — or use the Kilowatts to Horsepower converter, which is the same calculation reversed.
Worked example
Given 500 hp, multiplying by 0.745699872 yields 372.849936 kW.
500 hp × 0.745699872 = 372.849936 kW
The converter above does this for any value you type, in either direction.
What is a horsepower?
Mechanical horsepower is the traditional English-speaking unit of engine power.
Definition: Defined as 550 foot-pounds per second, which is about 745.700 watts.
Where it is used: US and UK car, motorcycle and small-engine power ratings.
Worth knowing: Distinct from metric horsepower (PS), which is about 1.4% smaller — so the same engine scores slightly higher in PS than in hp.
What is a kilowatt?
A kilowatt is 1,000 watts, the practical unit for substantial electrical loads.
Definition: Exactly 1,000 watts.
Where it is used: Electric motor and vehicle output, heating systems, EV charger ratings, and solar array capacity.
Horsepower vs Kilowatts
The horsepower is an imperial unit while the kilowatt is a metric unit. That is why the factor between them is not a round number: the two systems were defined independently and only later tied together by exact agreement.
Frequently asked questions
How many kilowatts are in a horsepower?
One horsepower equals 0.745699872 kilowatts.
What is the formula to convert horsepower to kilowatts?
Multiply the number of horsepower by 0.745699872. To reverse it, divide by 0.745699872 instead.
How do I convert kilowatts back to horsepower?
Divide by 0.745699872, which is the same as multiplying by 1.34102209.
How many kilowatts are in 10 horsepower?
10 hp works out to 7.456999 kW.
Is there anything to watch out for with horsepower?
Distinct from metric horsepower (PS), which is about 1.4% smaller — so the same engine scores slightly higher in PS than in hp.
How is the horsepower defined?
Defined as 550 foot-pounds per second, which is about 745.700 watts.