Unit converter
Power.
Convert hp to kW, or pick any of the 13 units in the menus. Type in either box and the other follows. Energy per second, in the three horsepowers the motor industry uses plus the watts everything is actually specified in.
| hp | kW |
|---|---|
| 1 hp | 0.7457 kW |
| 2 hp | 1.4914 kW |
| 3 hp | 2.2371 kW |
| 4 hp | 2.9828 kW |
| 5 hp | 3.7285 kW |
| 10 hp | 7.457 kW |
| 15 hp | 11.1855 kW |
| 20 hp | 14.914 kW |
| 25 hp | 18.6425 kW |
| 50 hp | 37.285 kW |
| 75 hp | 55.9275 kW |
| 100 hp | 74.57 kW |
| 250 hp | 186.425 kW |
| 500 hp | 372.85 kW |
| 1000 hp | 745.7 kW |
- Every unit in the menus is defined against W, so any pairing converts by the same single route.
Definitions
- Mechanical horsepower is 745.6999 W, defined as 550 foot-pounds per second. It is the horsepower UK and US brochures quote.
- The kilowatt is 1000 watts. EU vehicle documents give engine power in kW, whatever the brochure says.
- Every unit here is defined against the W.
- 12 of the 13 units are exact by definition; the rest are conventional or measured values. The display says which kind you are looking at.
How it works
Every value is converted into watts and then back out into the unit you asked for. One route covers every pairing in the menus, so an unusual combination is no less accurate than a common one, and adding a unit affects only that unit.
Both boxes are live. Whichever one you last typed in is the source, changing either menu recalculates straight away, and Swap exchanges the units and the values so the number you are reading stays where you are looking.
Display precision limits significant figures rather than decimal places, because one fixed number of decimals is useless across a range this wide. Very large and very small results switch to scientific notation with a proper superscript exponent. The editable box always holds a plain number at full working precision, so you can carry on from either side.
Common questions this answers: how many kilowatts in a horsepower (mechanical) (0.7457), how many mechanical horsepower in a kilowatt (1.34102), and what 100 hp is in kilowatts (74.57 kW).
Common conversions
- Mechanical horsepower to kilowatts
- Kilowatts to mechanical horsepower
- Metric horsepower to mechanical horsepower
- Watts to BTU per hour
- All converters
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- Works offline once loaded
From the maker of Ans — a scientific calculator you can own. Same idea: a proper instrument, nothing in the way.