Enter the measured three-phase power and the input power at full-rated load into the calculator to determine the motor load percentage.

The following formula is used to calculate the motor load of an electric motor.

L = Pm / Pi *100
• Where L is the motor load (%)
• Pm is the measured three-phase power (kW)
• Pi is the Input Power at full-rated load (kW)

To calculate the motor load, divide the three-phase power by the input power, then multiply by 100.

A motor load is defined as the ratio of the measured power to the full rated power that a motor is running at. This ratio can be expressed in percentage by multiplying it by 100 as seen in the formula above.

1. First, determine the measured three-phase power.

For this example, the measured power is found to be 500 kW using the current and amps.

2. Next, determine the full-rated load.

This is most often published data by the manufacturer of the motor. For this problem, the rated load is 1000 kW.

3. Finally, calculate the motor load.

The motor load can be calculated using the formula above. ML = Pm/PI *100 = 500/1000 *100 = 50%.