Two ways to get a horsepower number: from a torque figure and RPM (dyno or spec-sheet math), or estimated from a drag strip time slip. Pick the tab that matches what you actually have.
Your Numbers
The exact math a dyno sheet uses to turn measured torque into horsepower at each RPM point.
From a dyno pull, a torque spec sheet, or your own measurement. This is exact math, not an estimate — the accuracy of the result only depends on the accuracy of your torque number.
Result
Updates live as you type.
Horsepower
307HP
—
Torque × RPM1,612,000
÷ 5252 (constant where torque = HP)5252
Horsepower307.0 HP
Kilowatts (kW)228.9 kW
Why 5252: horsepower and torque are always equal at exactly 5252 RPM, by definition of how horsepower is derived from torque (1 HP = 33,000 ft·lb/min; work that out per revolution at a given RPM and 5252 is where the units cross). Below 5252 RPM, torque > HP; above it, HP > torque — this isn’t a tuning fact about your engine, it’s just the math.
Your Numbers
Classic drag-racing rule-of-thumb formulas (Roger Huntington’s ET method, and the trap-speed method) — estimates, not dyno-accurate.
Enter both if you have them — the two methods should land close together; a big gap usually means a bad launch, wheelspin, or a timing-slip misread rather than a math problem.
Result
Updates live as you type.
Estimated Horsepower
412HP
Two estimates below — average shown above
From ET: weight ÷ (ET ÷ 5.825)³—
From trap speed: weight × (mph ÷ 234)³—
Average estimate—
Why this is an estimate, not a measurement: these formulas back-calculate flywheel horsepower from weight and track performance, assuming a clean launch, good traction, sea-level density altitude, and typical drivetrain loss. Wheelspin, a bad 60-foot, altitude, temperature, and driveline type (manual vs. auto vs. AWD) can shift the real number meaningfully. Treat this as a ballpark, not a dyno-equivalent figure — a real dyno pull (see the Torque & RPM tab) is always more accurate if you have one.
