Engine Horsepower Calculator

Estimate engine horsepower using the ET or trap speed method.

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Engine Horsepower Calculator

Estimate HP from 1/4 mile elapsed time (ET)

Vehicle Weight (lbs)

1/4 Mile ET (seconds)

Engine Horsepower Calculator

Engine horsepower can be estimated using several methods: from torque and RPM, from trap speed at the drag strip, or using the Engine HP formula based on elapsed time and vehicle weight. Our calculator uses the most common methods to estimate brake horsepower (BHP) or wheel horsepower (WHP).

Common Uses

Estimating engine power from drag race performance
Converting torque and RPM to horsepower
Comparing engine output across vehicles
Automotive enthusiast and racing applications

Frequently Asked Questions

What is the formula to calculate HP from torque?

HP = (Torque × RPM) / 5,252. This formula works because 1 horsepower equals 5,252 ft-lb/min. Example: 300 ft-lb of torque at 4,000 RPM: (300 × 4000) / 5252 = 228.5 HP. Torque and HP curves always cross at 5,252 RPM.

What is the ET (elapsed time) method?

Developed by empirical testing at drag strips: HP = Weight × (Speed / 234)³. Example: A 3,000 lb car running a 12.5-second quarter mile at 110 mph: HP ≈ 3000 × (110/234)³ ≈ 312 HP. This method provides a useful estimate from drag strip timing data.

Is this calculator free to use?

Yes. All calculators on zenicalculator.com are completely free with no registration required.

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