PTO torque calculator
Estimate steady-state shaft torque from PTO output power and rotational speed.
Your estimate
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How the calculation works
Power is torque multiplied by angular speed. The tool uses PTO shaft output, not engine power. US horsepower means mechanical horsepower (1 hp = 0.7456998716 kW); torque is also shown in pound-feet. Rotation speed remains rpm in both unit systems.
This steady-state estimate does not size or certify a driveshaft. Shock loading, starting loads, geometry and manufacturer ratings are outside this calculation. Use the implement’s documented PTO speed; changing the calculator speed does not approve a different operating speed.
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Formula & reference sources
- Penn State Extension — PTO power and machinery ratings
- Parker Hannifin — Motor torque and power formulas
See our methodology for unit definitions and evidence boundaries.