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ET Predictor Calculator
Predict elapsed time from weight and horsepower
The ET predictor estimates the quarter-mile elapsed time a combination should run, from its weight and flywheel horsepower.
Formula: ET = 5.825 × (Weight ÷ HP)^⅓
What this number means
This predicts quarter-mile ET from vehicle weight and horsepower, assuming a reasonably sorted car that hooks and is geared sensibly. It is a planning estimate, not a guarantee — traction and drivetrain losses move real cars off the line in both directions.
What to change next
Use it to set a realistic dial-in starting point or a build target before spending money. If your actual ET is far slower than predicted, audit sixty-foot, gearing and converter slip before chasing more power.
Worked example
3,000 lb with 450 hp predicts ≈ 10.96 seconds in the quarter.