kW to Nm Calculator

Convert power (kilowatts) to torque (Newton-meters) using rotational speed. Essential calculator for engines, motors, EVs, and mechanical engineering applications.

Engineering Tool:

Calculate torque from power and RPM. Supports reverse calculations and multiple engineering units for professional mechanical analysis.

Power to Torque Calculator

Calculation Mode

Power unit for kW→Nm mode, Torque unit for Nm→kW mode

Rotational speed in revolutions per minute or radians per second

Calculation Results

Enter values and click Calculate

Convert Power Into Torque the Right Way

Power and torque are closely connected, but they are not interchangeable. A kW to Nm Calculator helps convert power into torque by using rotational speed (RPM). Without RPM, torque cannot be calculated accurately—this is why a proper calculator matters.

This tool is commonly used in automotive engineering, electric motors, industrial machines, and performance analysis.

Why RPM Is Required

Kilowatts measure power, while Newton-meters measure rotational force. RPM defines how fast the system rotates. The same power value can produce very different torque levels at different speeds.

For example, 10 kW at 1500 RPM produces 63.7 Nm of torque, but the same power at 3000 RPM produces only 31.8 Nm. Speed matters.

Formula Used in the Calculator

The standard engineering formula is:

Torque (Nm) = (Power (kW) × 9550) ÷ RPM
Primary calculation: kW to Nm

For reverse calculation:

Power (kW) = (Torque (Nm) × RPM) ÷ 9550
Reverse calculation: Nm to kW

Power to Torque Conversion Examples

Here are examples of kW to Nm conversions at different RPM values:

Power (kW) RPM Torque (Nm) Application
10 1500 63.7 Diesel engine idle
20 3000 63.7 Electric motor
50 2000 238.8 Industrial pump
75 4000 179.1 High-speed motor
5 1000 47.8 Low-speed application
100 6000 159.2 High-performance engine
25 1800 132.6 Generator set
15 2500 57.3 Automotive application
40 3500 109.1 Turbocharged engine
8 1200 63.7 Heavy machinery
60 5000 114.6 Racing application
30 2200 130.0 Industrial motor
12 800 143.2 Low-RPM application
90 4500 191.1 High-power system
6 900 63.7 Small motor
45 3200 134.3 Marine application
18 2800 61.4 HVAC system
55 3800 138.0 Construction equipment
22 1600 131.3 Agricultural machinery
35 2600 128.5 Power generation
9 1100 78.2 Material handling
70 4200 159.2 Aerospace application
28 2400 111.4 Manufacturing equipment
42 3000 133.7 Process industry

What Makes This Calculator Useful

  • Supports multiple power units (kW, HP, PS, Watts)
  • Handles reverse calculations (Nm to kW)
  • Works with different speed units (RPM, rad/s)
  • Converts to multiple torque units (Nm, lb-ft, kg-m)
  • Shows accurate real-world results for engineering applications

Who Should Use It

  • Mechanical engineers analyzing motor and engine performance
  • Automotive designers calculating drivetrain requirements
  • EV engineers optimizing electric motor efficiency
  • Students learning power-torque relationships
  • Technicians troubleshooting mechanical systems

Torque is not guessed—it is calculated. By combining power with speed, this calculator delivers precise results you can trust for both learning and professional use.

Engineering Tip:

The constant 9550 in the formula comes from the relationship between watts and Newton-meters at different rotational speeds. It's a standard engineering constant for SI unit conversions.