How is power calculated from torque and RPM?
Power in kilowatts is calculated as torque in newton-metres multiplied by RPM, divided by 9549. Mechanical horsepower is then calculated from kW using a factor of 1.34102.
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Free workshop calculator
Torque to HP & kW Calculator
Enter torque and engine speed to estimate power instantly. The calculation runs locally and shows kW, mechanical HP and metric PS without registration.
Performance Tools
Convert torque and engine speed into estimated power.
Enter torque and RPM for an instant kW and HP estimate, then convert kW into mechanical HP and metric PS.
Manual input
Torque Power Calculator
Enter measured torque and RPM. Results update instantly.
Estimated power
193.2HP
Estimated power
144.1kW
kW to HP quick convert
Mechanical HP
187.7HP
Metric power
190.3PS
Calculation method
The formula behind the result.
The calculator does not guess from engine size or vehicle type. It uses the entered torque value at the entered engine speed.
Power in kilowatts
kW = Nm × RPM ÷ 9549Mechanical horsepower
HP = kW × 1.34102Metric horsepower
PS = kW × 1.35962Important limitation
An estimate, not a dyno certificateQuestions
Torque and power calculation FAQ
Is the result the same as a chassis dyno measurement?
No. The calculator estimates power at the point represented by the torque input. A chassis dyno also reflects drivetrain loss, measurement method, correction standard, gear selection and environmental conditions.
What is the difference between HP and PS?
HP here means mechanical horsepower. PS is metric horsepower. One kW equals approximately 1.34102 HP or 1.35962 PS.