Horsepower to kilowatts
One horsepower (mechanical) is 0.7457 kilowatt. Enter any value and the answer updates as you type.
Converter
Horsepower (mechanical) to Kilowatt at a glance
21 rows| Horsepower (mechanical) | Kilowatt |
|---|---|
| 1 hp | 0.7456998716 kW |
| 2 hp | 1.491399743 kW |
| 3 hp | 2.237099615 kW |
| 4 hp | 2.982799486 kW |
| 5 hp | 3.728499358 kW |
| 6 hp | 4.474199229 kW |
| 7 hp | 5.219899101 kW |
| 8 hp | 5.965598973 kW |
| 9 hp | 6.711298844 kW |
| 10 hp | 7.456998716 kW |
| 15 hp | 11.18549807 kW |
| 20 hp | 14.91399743 kW |
| 25 hp | 18.64249679 kW |
| 30 hp | 22.37099615 kW |
| 40 hp | 29.82799486 kW |
| 50 hp | 37.28499358 kW |
| 75 hp | 55.92749037 kW |
| 100 hp | 74.56998716 kW |
| 250 hp | 186.4249679 kW |
| 500 hp | 372.8499358 kW |
| 1,000 hp | 745.6998716 kW |
Quick pairs
tap to loadWhy people convert horsepower to kilowatts
Industrial generator and equipment rental listings split the same way vehicle spec sheets do: a diesel generator's engine is often rated in horsepower while its electrical output capacity is quoted in kilowatts, and renters comparing two units need both figures to line up. A rental generator with a 100 hp diesel engine driving an alternator rated at roughly 65 to 70 kW electrical output is normal, since engine horsepower and usable electrical kilowatts are not the same number even before any unit conversion, which is a separate efficiency loss on top of the 0.7457 conversion factor.
Electric motor nameplates add a second wrinkle: many motors list both a kilowatt rating (the electrical standard) and an equivalent horsepower rating in parentheses for buyers used to the older unit, and the two numbers on the plate are exactly 0.7457 apart, not independently measured, so checking the nameplate math is really just checking this one conversion.
How the horsepower (mechanical) to kilowatt conversion works
The exact multiplier comes straight from the two units' definitions: one mechanical horsepower is defined as 550 foot-pounds per second, and converting that to watts gives 745.6998716 watts, or 0.7456998716 kilowatts.
kW = hp × 0.7456998716
At small scale, a 5 hp lawnmower or go-kart engine converts to 5 × 0.7456998716 = 3.73 kW. A mid-size 250 hp car engine converts to 250 × 0.7456998716 = 186.42 kW. A 2,000 hp locomotive engine converts to 2,000 × 0.7456998716 = 1,491.40 kW, showing the same multiplier holds whether the source number has one digit or four.
Going the other way, multiply kilowatts by 1.341022090: a 100 kW electric motor is 100 × 1.341022090 = 134.10 hp.
Rounding to two decimal places on the kilowatt side is plenty for almost any real spec sheet, since manufacturers themselves round their published hp figures to the nearest whole number before the conversion is even applied.
The most common mistake with this specific pair is grabbing the wrong horsepower definition: mechanical horsepower (745.6998716 W), metric horsepower / PS (735.49875 W), and electrical horsepower (746 W) are all slightly different units that happen to share the name "horsepower," and mixing them up introduces a small but real error that compounds across a full spec sheet.
Questions
How many kilowatts are in 100 horsepower (mechanical)?
100 horsepower (mechanical) equals 100 × 0.7456998716 = 74.57 kilowatts.
How do I convert kilowatts back to horsepower (mechanical)?
Multiply the kilowatt figure by 1.341022090. A 150 kW motor, for example, is 150 × 1.341022090 ≈ 201.15 horsepower (mechanical).
Why do some spec sheets use horsepower and others kilowatts for the same kind of engine?
It is mostly regional convention: horsepower is the traditional unit in US and UK automotive marketing, while kilowatts are the SI-based unit used on most official vehicle registration documents and in most of the rest of the world, including on the same car model sold in different markets.
Is there a quick way to estimate kilowatts from horsepower without a calculator?
Roughly multiply by 0.75, or divide by 1.34. Either shortcut is accurate to within a few percent, which is close enough for ballpark comparisons, though the exact 0.7456998716 factor should be used for anything safety-critical like a generator sizing calculation.
What's the most common mistake when converting horsepower to kilowatts?
Using the wrong flavor of horsepower. Mechanical horsepower (745.7 W), metric horsepower / PS (735.5 W), and electrical horsepower (746 W) are all different units, and a spec sheet that doesn't say which one it means can leave a small conversion error baked into the result.
More on precision and what leaves your device: see About and Privacy policy.