Enter the RWKW into the calculator to convert the value into horsepower (HP).

RWKW ⇄ HP Calculator

Enter either RWkW or HP

Assumes 15% drivetrain loss (engine power ≈ rear-wheel power ÷ 0.85). Uses mechanical horsepower (1 hp = 0.745699872 kW).

RWKW to HP Formula

Assuming 15% drivetrain loss (engine power ≈ rear-wheel power ÷ 0.85), the following equation is used to estimate engine horsepower (HP) from RWKW.

HP ≈ RWKW * 1.578
  • Where HP is the engine (crank) horsepower
  • RWKW is the rear-wheel power in kilowatts (kW)

To calculate the HP from RWKW, divide RWKW by 0.85 to estimate engine kW (15% drivetrain loss), then convert kW to HP (1 kW ≈ 1.341 HP). This simplifies to multiplying RWKW by approximately 1.578.

Rear-Wheel kW to Engine Horsepower Conversion Table (15% drivetrain loss)
RWKW (kW) Horsepower (HP) Metric Horsepower (PS)
5078.88479.978
75118.325119.967
100157.767159.955
125197.209199.944
150236.651239.933
175276.093279.922
200315.535319.911
225354.976359.900
250394.418399.889
275433.860439.878
300473.302479.866
325512.744519.855
350552.186559.844
375591.627599.833
400631.069639.822
450709.953719.800
500788.837799.777
600946.604959.733
7001104.3711119.688
8001262.1381279.644
* Rounded to 3 decimals. Assumes 15% drivetrain loss (engine power ≈ RWKW ÷ 0.85). Constants: 1 hp = 0.745699872 kW; 1 PS = 0.98632 hp.

What is RWKW?

Definition:

RWKW, short for rear-wheel kilowatts, is a measure of the power in kilowatts at the driven wheels of a vehicle (typically measured on a chassis dynamometer).

How to convert RWKW to HP?

Example Problem:

The following example outlines the steps and information needed to convert RWKW to HP.

First, determine the power at the rear wheels. For this example, the power is 100 kW.

Next, estimate the engine power from the wheel power. Assuming 15% drivetrain loss, engine kW ≈ RWKW ÷ 0.85 = 100 ÷ 0.85 = 117.647 kW.

Finally, calculate the horsepower using the formula above:

HP = (RWKW ÷ 0.85) ÷ 0.745699872

HP = 117.647 ÷ 0.745699872

HP = 157.767