Enter the motor efficiency (%), the applied voltage (volts), power factor, and the current (amps) into the calculator to determine the Motor Absorbed Power. 

Motor Absorbed Power Formula

The following formula is used to calculate the Motor Absorbed Power.

Pa = (n/100)* SQRT(3) * V * I * p.f.
  • Where Pa is the Motor Absorbed Power (watts)
  • n is the motor efficiency (%) 
  • V is the applied voltage (volts) 
  • I is the current (amps) 
  • p.f is the power factor

To calculate the motor absorbed power, multiply the efficiency by the square root of 3 times the voltage, current, and power factor.

How to Calculate Motor Absorbed Power?

The following example problems outline how to calculate Motor Absorbed Power.

Example Problem #1

  1. First, determine the motor efficiency (%). In this example, the motor efficiency (%) is determined to be 45 .
  2. Next, determine the applied voltage (volts). For this problem, the applied voltage (volts) is measured to be 100 .
  3. Next, determine the current (amps). In this case, the current (amps) is found to be 54.
  4. Next, determine the power factor. For this problem, this is .50.
  5. Finally, calculate the Motor Absorbed Power using the formula above: 

Pa = (n/100)* SQRT(3) * V * I * p.f.

Inserting the values from above and solving yields: 

Pa = (45/100)* SQRT(3) * 100 * 54 * .50 = 2104.44 (watts)

Example Problem #2

Using the same method as above, determine the variables required by the formula. For this example problem, these are:

motor efficiency (%) = 75

applied voltage (volts) = 500

current (amps) = 13

power factor = 3.4

Enter these given values into the calculator or above yields: 

Pa = (75/100)* SQRT(3) * 500 * 13 * 3.4 = 28,708.742 (watts)