BHP Per Tonne Calculator – Power-to-Weight Ratio

Power Output

Wheel Power (WHP)

Loss %

Vehicle Weight

Add Driver / Cargo?

Driver Weight

Cargo Weight

BHP Per Tonne

0kW / Tonne

0BHP / kg

BHP/Tonne	Feel
< 100	Economical
< 150	Sporty Hatch
< 200	Hot Hatch
< 300	Sports Car
< 500	Supercar
> 500	Hypercar

What is BHP Per Tonne?

Brake Horsepower (BHP) per tonne is the ultimate metric for comparing vehicle performance. It levels the playing field between lightweight sports cars, heavy electric vehicles (EVs), and motorcycles by calculating how much power is available to move every metric tonne (1,000 kg) of weight.

A higher power-to-weight ratio generally means faster acceleration and better hill-climbing ability. For example, a light car with 200 BHP will often outrun a heavy SUV with 300 BHP because it has less mass to move.

How to Calculate BHP Per Tonne

The formula is straightforward. First, ensure your weight is in metric tonnes (1 tonne = 1,000 kg).

BHP Per Tonne = BHP ÷ (Weight in kg ÷ 1000)

Example 1 (Hot Hatch): A car has 200 BHP and weighs 1,400 kg (1.4 tonnes).
Calculation: 200 ÷ 1.4 = 142.8 BHP/Tonne.

Example 2 (Supercar): A car has 600 BHP and weighs 1,500 kg (1.5 tonnes).
Calculation: 600 ÷ 1.5 = 400 BHP/Tonne.

Frequently Asked Questions

What is a “good” BHP per tonne?

For many everyday cars, around 80–120 BHP/tonne is typical. 150–200 often feels quick, 200–300 is very fast for the road, and 300+ is usually high-performance or supercar territory.

Should I use Kerb Weight or Gross Vehicle Weight?

Use kerb weight for the best apples-to-apples comparison between vehicles (as the manufacturer supplies it). Use GVW if you want a real-world figure when the vehicle is fully loaded with passengers, cargo, or tools.

What is the difference between Wheel HP and Flywheel HP?

Wheel horsepower (WHP) is measured at the wheels and is usually lower because of drivetrain losses. Flywheel (crank) horsepower is measured at the engine. If you only know WHP, you can estimate flywheel power by applying a drivetrain loss percentage.

Metric Tonne vs UK Long Ton vs US Short Ton?

A metric tonne is 1,000 kg. A UK long ton is 2,240 lb (about 1,016 kg). A US short ton is 2,000 lb (about 907 kg). For UK vehicle comparisons, metric tonnes are most common, but this calculator supports all three.