CALCZERO.COM

Electric Motors

Motor Torque Calculator

Motor Torque reports shaft torque from one operating case.

Enter values for shaft torque

Use one consistent electrical operating case for all fields.

kW

Enter shaft power in kW.

rpm

Enter speed in rpm.

How Motor Torque works

For Motor Torque, use torque = 9550 × kW ÷ rpm. Motor Torque uses Shaft power, Speed to report Shaft torque.

With the loaded values, shaft torque evaluates to 49.40 N·m. Test shaft power separately and preserve the baseline shaft torque.

Inputs for Motor Torque

Shaft power and Speed belong to Motor Torque. Keep source units with shaft power.

The Motor Torque defaults demonstrate arithmetic only. Replace shaft power with case-specific data. For starting current, use Motor Starting Current Calculator.

Shaft power
Example entry: 7.5 kW.
Speed
Example entry: 1450 rpm.

Reading the Motor Torque result

This output represents Motor Torque. If the next question concerns mechanical power, open Horsepower Kilowatt Calculator.

Before selecting equipment for Motor Torque, compare shaft torque with available ratings and operating limits.

Measurement and units

Motor nameplate data, duty, enclosure, starting method, load profile, and thermal limits govern final selection. Check prefixes on shaft power.

Keep the shaft power unit and measurement point consistent across Motor Torque cases.

Limits of this calculation

This is average steady shaft torque.

Only the listed Motor Torque inputs contribute to shaft torque. Unentered effects remain outside Motor Torque. Use Motor Poles Frequency Calculator as the follow-up for required pole count.

A useful Motor Torque comparison

Record shaft torque before testing a different shaft power value. Starting demand belongs in the separate Motor Starting kVA worksheet.

Document the alternate shaft power source.

Questions about Motor Torque

What does Motor Torque calculate?

Motor Torque reports shaft torque.

Can Shaft power be zero?

For Motor Torque, measure any zero shaft power directly.

Why can shaft torque differ from measurement?

This is average steady shaft torque. Recheck shaft power.

Should the result be rounded?

Keep extra digits while comparing cases, then round to the precision supported by shaft power.