About the Quarter Mile Calculator
Estimated quarter-mile time and trap speed from power and weight, using the classic formulas.
Also known as: et calculator, drag strip calculator, trap speed calculator, 1/4 mile time.
How to use this calculator
- Enter power, weight, driver and fuel.
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Review the breakdown shown under the main result.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
ET = 5.825 × (weight ÷ power)^⅓ · trap = 234 × (power ÷ weight)^⅓
Worked example
Using the values pre-filled in the calculator above:
- Power = 300 hp
- Weight = 1,500 kg
- Driver and fuel = 90 kg
the calculator returns:
- Quarter mile time: 13.218 seconds
- Trap speed: 103.12 mph
- Trap speed in km/h: 166
- Power to weight: 188.7 hp/tonne