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ratio

Power-to-weight calculator

Power-to-weight ratio calculator.

Enter power and weight to get kW per tonne and every other common unit, see which tier your car falls in, and which cars sit closest.

Use kerb weight for comparing cars. For the P-plate test, use tare mass from the registration papers instead.

Power-to-weight

107kW/t

hp/t
144
PS/t
146
kg/kW
9.3
lb/hp
15.3

Everyday

Mainstream hatches, sedans and SUVs. Enough power to notice good tyres in the wet.

Your car sits at 107 kilowatts per tonne. Reference cars: Picanto 62, Corolla 93, MX-5 127, Golf GTI 136, Civic Type R 164, BMW M3 217, 911 GT3 261, Ferrari 296 396, Rimac Nevera 612 kilowatts per tonne.

Closest: Suzuki Swift Sport (ZC33S) (104), Toyota Sprinter Trueno GT-APEX (AE86) (102), Mazda 3 G25 (100), Toyota Camry Hybrid (XV70) (100)

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Power-to-weight questions

How do you calculate power-to-weight ratio?

Divide power by mass. In kW per tonne: power in kW ÷ mass in kg × 1,000. A 150 kW car weighing 1,400 kg is 150 ÷ 1,400 × 1,000 = 107 kW/t. For hp per tonne, use horsepower instead of kW.

What is a good power-to-weight ratio?

Most family cars sit between 60 and 100 kW/t. Hot hatches run 130 to 160, sports cars 170 to 250, and supercars 300 or more. For P-platers in NSW, Victoria and Queensland the limit is 130 kW/t on tare mass.

Should I use kerb weight or tare mass?

Kerb weight (with fluids and a full tank, no driver) is the fairest way to compare cars, and it's what manufacturers usually quote. The P-plate rules use tare mass from the registration papers, which is lighter, so the legal ratio is a little higher.

Why does power-to-weight matter for tyres?

It tracks how hard the tyres are worked: how much force they transmit accelerating, how much heat they soak up, and how quickly a cheap compound runs out of grip, especially in the wet. ratio uses it to set the minimum tyre category a car should run.