Quarter-Mile Performance Calculator

When to use it

• Compare how a change in race weight affects estimated quarter-mile et before committing to parts, setup, or strategy changes.
• Check a workshop, dyno, simulator, or trackside spreadsheet result using a transparent formula: 5.825 × (weight ÷ power)^(1/3).
• Use the result to plan scenarios, then update it with live timing, weather, safety-car probability, fuel logs, tyre wear, and any sporting regulations that affect refuelling or pit timing.

How to use it

1. Enter race weight in lb; the default value shown is 3,300 lb.
2. Enter engine power in hp; the default value shown is 500 hp.

How to read the result

Estimated quarter-mile ET is shown in seconds. Use the number as a calculated reference point, then compare it with measured data from the car, the part supplier, or the race environment. A mathematically clean answer can still be unsuitable if the inputs are estimated, rounded, measured under different conditions, or outside the normal range for the vehicle.

Assumptions and checks

• An empirical ideal estimate. Traction, gearing, aero, weather, launch and driver execution materially affect the result.
• Changing race weight and engine power together can move the answer in ways that are easy to miss, so make related setup changes deliberately.
• Add a reserve for formation laps, safety-car periods, traffic, and unexpected consumption changes.
• Check the race rules before assuming refuelling, stint length, or pit-stop timing is allowed.
• Compare estimates with logged data from the same car, driver, tyre, and circuit where possible.