Same input, every power unit — tap a tile to set the right-hand unit.
Horsepower, kilowatts, and metric PS
Mechanical hp and brake horsepower (bhp) share the same constant: 1 hp ≈ 0.7457 kW.
Metric horsepower (PS / CV / ch) is 1 PS ≈ 0.7355 kW — about 1.4% smaller than mechanical hp.
A “400 hp” US claim is about 298 kW or 406 PS, not 400 PS.
Power converters exist because brochures, dyno sheets, and service manuals do not agree on a unit. A German TÜV paper in PS, a US crate-engine sticker in hp, and an Australian ADR figure in kW can describe the same engine and still print three different numbers.
This page converts the four labels you actually see in the shop: mechanical horsepower, brake horsepower, metric PS, and kilowatts. It does not estimate horsepower from torque — that is a different formula on the horsepower calculator. If you only have a torque figure and an RPM, go there instead of converting a guessed HP.
Use the board when a graph mixes units (kW on one axis, hp in the title). Leave hp and PS as separate tiles so a 400 PS Euro claim does not get filed next to a 400 hp LS as if they were equal.
Common power conversions
These are the pairs that show up on crate tags and dyno printouts. Enter your exact figure above — a 6 hp gap on a 400 hp claim is the hp vs PS constant, not a dyno error.
Horsepower, kilowatts, and metric PS
You have
Equals
Also
400 hp
298 kW
406 PS
300 kW
402 hp
408 PS
400 PS
294 kW
395 hp
250 bhp
186 kW
253 PS
100 hp
74.6 kW
101 PS
1 hp (mech.) = 1 bhp ≈ 0.7457 kW. 1 PS ≈ 0.7355 kW. Rounded to whole power units.
When this is the wrong tool
Converting 400 lb·ft into horsepower is not a unit conversion. You need RPM and the 5252 formula — use the horsepower calculator. Quarter-mile ET from a power number belongs on the quarter-mile calculator, not this board.
How to convert horsepower and kilowatts
Enter the advertised figure. Type the number from the crate tag, dyno sheet, or brochure.
Set the source unit. Pick hp, bhp, PS, or kW to match what was printed — do not assume hp and PS are interchangeable.
Read the board. Every power unit updates at once. Tap a tile to move that unit to the right-hand card.
Power converter FAQ
No. One mechanical horsepower is about 0.746 kW; one metric horsepower (PS/CV) is about 0.735 kW. On a 400 hp claim the gap is a few horsepower — enough to matter when you compare dyno graphs from different regions.
Different constants. 400 hp ≈ 298 kW ≈ 406 PS. Leave hp and PS as separate units so a German brochure and a US dyno sheet stay honest.
Brake horsepower is mechanical horsepower measured at the crank (or a brake dyno). This converter treats hp and bhp as the same constant. It does not add drivetrain loss — a 400 hp crank figure is not 400 whp.
1 mechanical hp ≈ 0.7457 kW. 1 metric PS ≈ 0.7355 kW. Pick the unit that matches the paper you are reading.