Hp to weight ratio calculator
Power to weight takes two figures, power and mass, and the answer is only meaningful once both are in matching units. The calculator above handles that conversion step, and the numbers below show what the result should look like.
12 × 12 = 144
Adding 12 to itself 12 times gives the same answer.
The two figures you need
Power to weight is horsepower against mass. Quote it one of two ways, and say which one you mean, because they are inverses of each other.
- hp per tonne = horsepower ÷ weight in tonnes. Higher is quicker.
- kg per hp or lb per hp = weight ÷ horsepower. Lower is quicker.
Get the units right first
This is the step the calculator above does. Enter your figure and the multiplier.
| From | To | Multiply by |
|---|---|---|
| kW | hp | 1.341 |
| hp | kW | 0.7457 |
| pounds | kilograms | 0.4536 |
| tonnes | kilograms | 1000 |
| hp per kg | hp per tonne | 1000 |
Worked examples
| Power | Mass | hp per tonne | kg per hp |
|---|---|---|---|
| 150 hp | 1,200 kg | 125 | 8.00 |
| 300 hp | 1,500 kg | 200 | 5.00 |
| 700 hp | 1,600 kg | 437.5 | 2.29 |
When the number looks wrong
A result below 1 means you divided by kilograms instead of tonnes; multiply it by 1,000. A result in the thousands means you divided the wrong way round. Also check which mass you used: published kerb weights leave out the driver, fuel and luggage, so a real-world figure is always a little worse than a brochure one. Compare like with like.
Other two-number ratios work the same way, such as the waist to height ratio and the golden ratio calculator. The full list is on the calculators page.