Motor

From input to answer.

Open All Tools → Motor and choose Single phase or Three phase.
Enter the known operating values. Shaft output can be entered in mechanical hp or kW.
For a current estimate, supply line voltage, shaft output, efficiency and power factor. Use percentages in percentage fields.
Read running current and the input/output power breakdown. Compare with the equipment nameplate and actual duty.

WORKED EXAMPLE

Running current for a 10 hp motor

Enter

Choose three phase, 10 hp shaft output, 600 V, 90% efficiency and 85% power factor.

Read the result

The calculated running current is about 9.38 A. Shaft output is about 7.457 kW and electrical input is about 8.286 kW.

Get more from it.

Shaft power is useful mechanical output, not electrical input. Efficiency connects the two.
Use line-to-line voltage for the three-phase case.

Know the limits.

This is an operating estimate, not a code full-load-current table or a starting-current calculation.
Do not use this result alone to select conductors, overloads, short-circuit protection or a drive.

Verify the inputs, applicable local requirements and real conditions. The app is a calculation aid and can contain errors. See our terms and safety disclaimer.

Common questions.

Why does this differ from a code-table current?

The estimate uses your efficiency and power factor. Prescribed design currents and actual nameplate values serve different purposes.