Can I use motor nameplate power?

Use an allowable power at the measured shaft and operating speed. A motor nameplate alone may not reflect gearbox losses or reduced-speed duty.

Does this calculate electrical consumption?

No. The result is mechanical shaft power. Electrical input requires measured electrical power or a separately justified drive efficiency.

What if torque changes throughout the batch?

Use simultaneous torque and speed records. Calculate each operating point; multiplying unrelated averages can misstate mean power.

Does sufficient power guarantee good mixing?

No. Impeller geometry, material behavior, circulation, and mixing time also control the result. Verify product uniformity with your established sampling method.

Mixing, Blending & Industrial Batch Processing calculator

Agitator Shaft Power Calculator

Calculate the mechanical power transmitted by your agitator shaft. Enter simultaneous torque and speed measurements, the shaft power allowance, and the working batch volume.

What this calculator does

Calculate mechanical agitator shaft power from measured torque and speed, then compare it with your entered shaft power allowance.

Formula used

Shaft power = torque × 2π × shaft speed ÷ 60,000
Power allowance used = shaft power ÷ allowable shaft power × 100
Power headroom = allowable shaft power − shaft power
Power density = shaft power × 1,000 ÷ batch volume

Inputs explained

Measured Shaft Torque: Torque measured at the agitator shaft during steady mixing.
Measured Shaft Speed: Simultaneous agitator shaft speed from the drive or tachometer.
Allowable Shaft Power: Approved power allowance at this shaft and operating speed.
Working Batch Volume: Actual material volume during the torque and speed measurement.

How to use the result

Best suited to agitator load survey, pilot power-density comparison.
Startup peaks, shaft torque limits, and motor cooling require separate checks. Mechanical shaft power excludes electrical and gearbox losses.

Common questions

Can I use motor nameplate power? Use an allowable power at the measured shaft and operating speed. A motor nameplate alone may not reflect gearbox losses or reduced-speed duty.
Does this calculate electrical consumption? No. The result is mechanical shaft power. Electrical input requires measured electrical power or a separately justified drive efficiency.
What if torque changes throughout the batch? Use simultaneous torque and speed records. Calculate each operating point; multiplying unrelated averages can misstate mean power.
Does sufficient power guarantee good mixing? No. Impeller geometry, material behavior, circulation, and mixing time also control the result. Verify product uniformity with your established sampling method.

Last reviewed 2026-10-01.