Motor Load Calculator

Estimate motor electrical load from horsepower, amps, volts, phase type, efficiency, power factor, service factor, duty cycle, and quantity. This calculator shows running load, adjusted load, starting load, kW, kVA, amps, demand load, and panel capacity percentage.

Calculate Motor Load

Motor load is estimated from motor power, voltage, phase type, efficiency, power factor, service factor, and duty cycle.
Your result will appear here.

How the motor load calculator works

Motor power:
The calculator estimates motor output power from horsepower, watts, kW, or entered amps.

Electrical load:
It applies voltage, phase type, efficiency, power factor, quantity, service factor, and duty cycle.

Capacity check:
Motor load is compared to the selected panel or circuit capacity to estimate load percentage and remaining amps.

Why use a motor load calculator?

A motor load calculator helps estimate how much electrical load motors add to a circuit, panel, subpanel, generator, or service.

It can help with pumps, fans, compressors, conveyors, shop tools, HVAC motors, multiple motor groups, panel planning, and generator load planning.

What your result means

Your result shows running amps, adjusted amps, starting amps, running watts, running kW, running kVA, horsepower, input power, output power, capacity percentage, remaining amps, and multiple motor row estimates.

Motor load calculator formulas

Frequently asked questions

What is motor load?

Motor load is the electrical demand created by a motor while running, starting, or operating under a specific duty cycle.

How do I calculate motor load amps?

Estimate motor output watts from horsepower, then divide by voltage, efficiency, and power factor. For three-phase motors, also divide by √3.

Why is starting load higher than running load?

Motors can draw high inrush current during startup before they reach normal operating speed.

Can this size the final motor circuit?

No. This calculator is a planning estimate. Final motor circuit sizing should follow motor nameplate data, manufacturer instructions, electrical code, and local inspection requirements.