Torque to Horsepower Calculator (Engine Power)
Torque to horsepower calculator: engine power from torque and rpm, or torque from power, in hp, kW or PS.
P = τ · ω = τ · 2π n
How to use this calculator
- Choose the quantity you want under “Solve for”.
- Type the known values and pick their units: any combination works.
- The result updates as you type. Open “Show the steps” to see the substitution.
P = τ·ω, with ω = 2π·rpm/60. In US units, hp = lb·ft × rpm / 5 252.
Peak power usually occurs at higher rpm than peak torque.
Formula
P = τ · ω = τ · 2π n
| Symbol | Quantity | Units |
|---|---|---|
| τ | Torque | N·m, kN·m, N·cm, lbf·ft, lbf·in, kgf·m, ozf·in |
| n | Engine speed | Hz, kHz, MHz, GHz, THz, rpm |
| P | Power | W, mW, kW, MW, hp, PS, BTU/h, kcal/h |
Worked example
Given: τ = 200 N·m · n = 3 000 rpm
P = 2π n τ
Result: P = 84.2589 hp
Frequently asked questions
200 N·m at 3 000 rpm?
62.8 kW, about 84.3 hp.