Power converter: bhp, PS and kW

Horsepower (or bhp) is the measure used for most cars to tell how much oomph they have, but it isn't the only one that manufacturers use.

Pferdestärke, or PS for short, and kilowatts (kW) are both lesser-used units for determining a car's engine power that mostly show up in mainland Europe.

Our tool converts between the three, so you can quickly check how powerful a car is.  

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Carmakers sometimes quote the power outputs of their engines using different units, which can be confusing when you're trying to compare new cars. 

This calculator lets you convert quickly and easily between the three main measurements used – bhp, kW and PS.

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What is bhp?

Brake horsepower, or bhp, is one of the most widely used measures of engine power (alongside PS, see below). It's often not clear which unit manufacturers are using in their brochures. 

Unlike ‘horsepower’ (hp), which refers to an engine’s total output, brake horsepower looks only at the amount of energy left once other parts such as the gearbox, alternator and water pump have been powered. It's measured at the point of power going onto the road , not at the point where the power is generated by the car’s engine or motor.

Horsepower is simply an anglicised version of PS, and both figures are interchangeable.

Powerful engines have a higher bhp figure. For example, an entry-level Toyota iQ has a 68bhp engine, while a supercharged Jaguar XF packs 503bhp.

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PS explained

Although it’s still commonly used by carmakers, PS or Pferdestärke (horse strength in German) was replaced by kW as the EU's ‘legal’ measurement of engine power in 1992. 

One PS is about 98.6% of a brake horsepower – the two are virtually interchangeable, and PS is sometimes referred to as 'metric horsepower'.

Measuring power in kilowatts

You may see some carmakers quoting the power of their engines in kilowatts – especially on the continent – and many manufacturers use this measurement in the UK now, showing this figure alongside either PS or hp figures. A kilowatt (kW) of power equates to around 1.34bhp.

What is torque?

Torque refers to the amount of pulling power an engine delivers when working at different speeds. The more torque an engine has, the more pull (or acceleration) it offers at lower revs.

Torque is nearly always discussed alongside brake horsepower, as it gives clues to how quickly the engine will be able to shift the car’s weight when overtaking or pulling away from traffic lights.

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