Torque to kW Calculator

Convert torque in newton-metres and RPM into kilowatts instantly.

Torque to kW Calculator
RESULT

This calculator converts torque in newton-metres and engine speed in RPM directly into power in kilowatts — the metric equivalent of the 5252 horsepower rule.

Quick answer: kW = (Torque in Nm × RPM) ÷ 9549. So 300 Nm at 4,000 RPM is about 125.7 kW.

Torque to kW Formula

Formula
kW = (Torque [Nm] × RPM) ÷ 9549
The metric counterpart to HP = (lb-ft × RPM) ÷ 5252.

The constant 9549 comes from converting radians per second and newton-metres into watts (it equals 60 × 1000 ÷ 2π). If your torque is in pound-feet, convert first (1 lb-ft = 1.3558 Nm) or use the imperial torque to HP calculator.

How to Use This Calculator

  1. Enter torque in newton-metres.
  2. Enter engine speed in RPM.
  3. Read kilowatts instantly, with the horsepower equivalent shown below.

Worked Example

Worked Example
1. kW = (300 × 4000) ÷ 9549
2. = 125.7 kW (≈ 168.5 HP)
calchorsepower.com Engineering Team
Automotive & mechanical calculation specialists

This calculator uses standard published formulas, verified against known input/output pairs.

✓ Formula verified

Frequently Asked Questions

Use kW = (Torque in Nm × RPM) ÷ 9549. You need both the torque and the RPM at which it occurs.

It converts newton-metres and RPM into kilowatts, derived from 60,000 ÷ 2π. It's the metric equivalent of the 5252 constant used with pound-feet.

Convert to newton-metres first by multiplying by 1.3558, or use our torque to HP calculator which works in imperial units.

No. Power depends on how fast the torque is delivered, so RPM is required.

Multiply kilowatts by 1.341 to get mechanical horsepower.