Convert Horsepower to Kilowatts
Horsepower to kilowatts is the conversion you need when a car or motor is rated in horsepower but you want its output in kilowatts, the unit used on most international spec sheets. One horsepower is approximately 0.7456998715822702 kilowatts — roughly 0.7457 — so the kilowatt number comes out smaller. This is the mechanical (imperial) horsepower used for US and UK car engines.
Horsepower (mechanical) to Kilowatts conversion table
| Horsepower (mechanical) (hp) | Kilowatts (kW) |
|---|---|
| 1 | 0.7457 |
| 2 | 1.4914 |
| 3 | 2.2371 |
| 5 | 3.728499 |
| 10 | 7.456999 |
| 20 | 14.913997 |
| 50 | 37.284994 |
| 100 | 74.569987 |
| 500 | 372.849936 |
| 1,000 | 745.699872 |
The formula
To convert horsepower to kilowatts, multiply the number of horsepower by 0.7456998715822702 (about 0.7457):
kilowatts = horsepower × 0.7456998715822702
A worked example
Say you have a 150-horsepower car and want its output in kilowatts:
150 × 0.7456998715822702 = 111.85498 kW
So a 150-horsepower car makes about 111.85 kilowatts.
Why it's an approximation
The horsepower here is the mechanical (imperial) horsepower, defined as 550 foot-pounds-force per second. That imperial definition doesn't divide evenly into the watt, so one horsepower works out to a long, non-terminating 0.7456998715822702 kilowatts — usually rounded to about 0.7457. Because the underlying numbers don't line up cleanly, the result stays approximate. This is also slightly larger than the metric horsepower (PS) seen on European spec sheets.
When you'll use it
Comparing a US or UK car's horsepower rating against the kilowatt figures used on international spec sheets, in EV listings, and in physics and electrical work.
Frequently asked questions
How many kilowatts are in one horsepower?
About 0.7456998715822702 kilowatts, or roughly 0.7457. It's a rounded figure — the mechanical horsepower doesn't convert to a clean, terminating number, so 0.7457 is the handy value to remember.
Is this the horsepower on European spec sheets?
No. This is the mechanical (imperial) horsepower, common on US and UK car engines. European sheets usually list metric horsepower (PS or CV) alongside kilowatts, and metric horsepower is about 1.4% smaller than this one, so check which rating you have.
Is the horsepower to kilowatts conversion exact?
No. The mechanical horsepower is built from imperial units that don't line up cleanly with the watt, so 0.7456998715822702 is rounded. Roughly 0.7457 works for everyday use; add decimals for more precision.