Torque to Horsepower Calculator

Free Torque to Horsepower Calculator - estimate engine HP and kW from torque and RPM with multiple torque unit options.

958.0K uses Updated · 2026-05-12 Runs locally · zero upload
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How to Use Torque to Horsepower Calculator

The Torque to Horsepower Calculator turns torque + RPM into HP and kW, with input units of lbf·ft, N·m or kgf·m.

  1. Enter the torque - Pick lbf·ft, N·m or kgf·m as the unit.
  2. Enter RPM - Engine or motor rotational speed.
  3. Read HP and kW - The Torque to Horsepower Calculator also displays the torque converted to lbf·ft.

Formula & Theory - Torque to Horsepower Calculator

T(lbf·ft) = T(N·m) × 0.7375621493
T(lbf·ft) = T(kgf·m) × 7.2330138512
HP = T(lbf·ft) × RPM ÷ 5252
kW = HP × 0.7457

Assumptions and Limits

The result is mechanical (shaft) power. Real engine output varies with load, throttle and accessories.

Use Cases for Torque to Horsepower Calculator

  • Engines - Compare HP and kW from dyno torque curves.
  • Electric motors - Estimate output power.
  • Drivetrain design - Match motor torque to required HP.
  • Karting and racing - Quick HP estimates from torque sensors.

Frequently asked questions about Torque to Horsepower Calculator

What is the formula?

HP = T(lbf·ft) × RPM ÷ 5252. Internally, torque in N·m or kgf·m is converted to lbf·ft first.

Why 5252?

It comes from 33000 ft·lbf per minute (1 HP definition) divided by 2π. Where torque (lbf·ft) and HP curves cross, RPM = 5252.

How accurate is this?

The formula is exact for steady-state mechanical power. Real engines lose some power to friction and accessories.

Is my data stored?

No. All calculations happen in your browser; nothing is sent to a server.