How the Horsepower Calculator works.
mechanical hp = torque (lb-ft) × RPM ÷ 5,252Torque is normalized to pound-feet; rotational speed is revolutions per minute; output also converts hp to kilowatts.
Worked example for the Horsepower Calculator.
An engine producing 300 lb-ft of torque at 5,252 rpm produces approximately 300 mechanical horsepower.
How to read this result.
The calculator derives mechanical horsepower from rotational torque and engine speed, covering both Engine Horsepower and Horsepower Calculator intent.
How this tool gets the answer
mechanical hp = torque (lb-ft) × RPM ÷ 5,252. Torque is normalized to pound-feet; rotational speed is revolutions per minute; output also converts hp to kilowatts. The calculator derives mechanical horsepower from rotational torque and engine speed, covering both Engine Horsepower and Horsepower Calculator intent.
A useful example
An engine producing 300 lb-ft of torque at 5,252 rpm produces approximately 300 mechanical horsepower. A quick way to verify the calculation is: Convert N·m to lb-ft when needed, multiply torque by RPM, divide by 5,252, and convert hp to kW using 0.7456998716 kW per hp.
What the result tells you
The calculator derives mechanical horsepower from rotational torque and engine speed, covering both Engine Horsepower and Horsepower Calculator intent. Torque may be entered as pound-feet or newton-metres and is normalized to pound-feet; output includes mechanical hp and kilowatts.
Where the answer can go wrong
Torque and RPM must be finite and nonnegative; RPM may be zero, which correctly produces zero power. Calculated crankshaft power does not include drivetrain loss, test correction standards, transient behavior, torque-curve variation, or measurement uncertainty.
Privacy and practical use
The calculation runs locally in your browser and FigureNest does not send the entered values to a calculation service. Keep the source value and its unit with any result you save so you can reproduce the calculation later.
Inputs and edge cases to check.
Torque and RPM must be finite and nonnegative; RPM may be zero, which correctly produces zero power.
What this tool does not include.
Calculated crankshaft power does not include drivetrain loss, test correction standards, transient behavior, torque-curve variation, or measurement uncertainty.
Reference guidance and methodology.
Horsepower Calculator questions.
What does the Horsepower Calculator do?
Calculate mechanical engine horsepower from torque and RPM, with kilowatt output.
How can I check the result?
Convert N·m to lb-ft when needed, multiply torque by RPM, divide by 5,252, and convert hp to kW using 0.7456998716 kW per hp.
Which units and assumptions matter?
Torque may be entered as pound-feet or newton-metres and is normalized to pound-feet; output includes mechanical hp and kilowatts. Calculated crankshaft power does not include drivetrain loss, test correction standards, transient behavior, torque-curve variation, or measurement uncertainty.
Are the entered values sent or stored?
No. The calculation runs locally in your browser and FigureNest does not send or store calculator inputs.