Engine Horsepower Calculator
Enter vehicle weight (lb) and quarter-mile time (s) to estimate horsepower with the classic formula.
Input Data
Results
216.1
At a glance:Classic estimate: HP = weight(lb) ÷ (quarter-mile time ÷ 5.825)³. Tuners use it to infer horsepower from acceleration results.
Formula
hp = weightLb ÷ (quarterMileTime ÷ 5.825)³.
How to Use
- Enter vehicle weight (lb) and quarter-mile time (s).
- Get the estimated horsepower instantly.
FAQ
Is this wheel horsepower?
The formula infers a horsepower figure consistent with the whole-car run, already including drivetrain loss — not a bare crank figure.
What is 5.825?
An empirical constant that makes common acceleration times map to reasonable horsepower ranges.
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References
Content reviewed by the Calculatorism editorial team. Results are for reference only; please refer to the relevant authorities for the official figures.