Electric Motor Energy Consumption Calculator

Calculate the yearly electricity (kWh) and cost of an electric motor from its power, load, efficiency and running hours.

Motor power (kW)

Load factor (0-1)

Efficiency η (%)

Hours / day

Days / year

Price (per kWh)

Input power drawn: — kW

Annual consumption: — kWh

Annual cost: —

Monthly cost: —

kWh = (P · load / η) · h/day · days/year

Cut the bill with a more efficient motor

Energy is the dominant lifetime cost of an industrial electric motor. Raising the efficiency class (IE3 → IE4 → IE5) lowers the input power for the same job. Estimate the upgrade benefit with our energy savings & payback calculator.

Frequently asked questions

How is a motor's energy consumption calculated?

Annual kWh = (P · load factor / η) · hours per day · days per year. The load factor and efficiency convert shaft power to the electrical input actually drawn.

Why divide by efficiency?

The nameplate kW is shaft (output) power; the grid supplies more because of losses. Input power = output / η, so a 93% motor draws ~7.5% more than its rated kW at full load.

How much can a higher efficiency class save?

It depends on running hours and price, but IE4/IE5 motors running continuously often save thousands of kWh per year versus older motors. Use the savings calculator for your numbers.

What load factor should I use?

Use the average fraction of rated power the motor delivers (0–1); 0.7–0.9 is typical for correctly sized motors.