WHP to kW and BHP Converter
Two conversions in one: the straight unit change from WHP to kW, and the drivetrain step that turns wheel power into the crank figure manufacturers quote.
Converting WHP to kW trips people up because two separate things are usually being asked at once. One is a straightforward unit change. The other involves adding back drivetrain losses. Mixing them up is how a 300 WHP car ends up quoted as anything from 224 to 263 kW.
The Two Different Steps
Step one is a unit conversion. Horsepower and kilowatts measure the same thing in different units, so 300 WHP is 223.7 kW measured at exactly the same place — the wheels. Multiply by 0.7457 and you are done. Nothing is added or removed.
Step two is a location change. Moving from wheel power to crank power means accounting for what the gearbox, driveshafts and differential absorb. That is an estimate, not a conversion, and it depends on the drivetrain layout.
Keep them separate and the arithmetic stays honest. If someone quotes "300 WHP = 263 kW", they have silently done both steps — which is fine, as long as everyone knows the kW figure is now a crank number being compared against a wheel number.
WHP to kW and BHP Chart
Crank figures below use 15% drivetrain loss, typical of rear-wheel drive.
| WHP | kW at wheels | Crank BHP (RWD) | kW at crank |
|---|---|---|---|
| 150 | 111.9 | 176 | 131.6 |
| 200 | 149.1 | 235 | 175.5 |
| 250 | 186.4 | 294 | 219.3 |
| 300 | 223.7 | 353 | 263.2 |
| 400 | 298.3 | 471 | 350.9 |
| 500 | 372.8 | 588 | 438.6 |
| 600 | 447.4 | 706 | 526.4 |
| 800 | 596.6 | 941 | 701.8 |
BHP, HP and WHP — What Each Term Means
- WHP — wheel horsepower, measured on a chassis dyno with the car's own drivetrain in the loop.
- BHP — brake horsepower, measured at the crankshaft on an engine dyno using a brake to apply load. The reference point manufacturers quote.
- HP — used loosely for either, which is precisely why confusion arises. Always check where the figure was measured.
In practice BHP and crank HP describe the same thing, though testing standards differ between manufacturers and eras — which is why some older quoted figures do not survive modern re-testing.
Why European Figures Are Usually kW
EU registration documents must state engine power in kilowatts, since kW is the SI unit. Manufacturers still print PS or BHP in brochures because buyers recognise them. If you are comparing a UK BHP figure against a German kW figure, remember the German brochure number may be PS rather than mechanical horsepower — and PS is about 1.4% smaller. Our kW to PS converter covers that distinction.
Related Conversions
For the drivetrain step on its own, use WHP to HP or the full WHP to HP chart. Going the other way, the wheel horsepower calculator estimates what a quoted crank figure should dyno at. For plain unit conversion without any drivetrain assumption, use HP to kW.
Frequently Asked Questions
Multiply WHP by 0.7457. So 300 WHP = 223.7 kW at the wheels. This is a pure unit conversion with no drivetrain adjustment.
223.7 kW at the wheels. At the crank, a rear-drive car at 15% loss gives about 353 BHP or 263.2 kW.
No. WHP is measured at the wheels with the drivetrain in the loop; BHP at the crankshaft on an engine dyno. BHP is always higher because it excludes drivetrain losses.
Two different questions. Unit conversion alone gives kW at the wheels; adding drivetrain loss gives kW at the crank. Both valid, not comparable to each other.
372.8 kW at the wheels — roughly 588 BHP or 438.6 kW at the crank on a rear-drive car.
Only after converting to the same reference point. Manufacturer figures are crank power; your dyno gives wheel power. Comparing directly makes any healthy car look down 15–25%.
No. PS is 735.5 W and mechanical BHP is 745.7 W, so PS is about 1.4% smaller. A 300 PS car is around 296 BHP.