Enter the root mean square current (amps) and the resistance (ohms) into the calculator to determine the Average Power. 

Average Power Formula

The following formula is used to calculate the Average Power. 

P = Irms^2 * R
  • Where P is the Average Power (watts)
  • Irms is the root mean square current (amps) 
  • R is the resistance (ohms) 

To calculate average power, multiply the root mean square current squared by the resistance.

How to Calculate Average Power?

The following two example problems outline how to calculate the Average Power.

Example Problem #1:

  1. First, determine the root mean square current (amps). In this example, the root mean square current (amps) is measured to be 1100.
  2. Next, determine the resistance (ohms). For this problem, the resistance (ohms) is calculated to be 1.3.
  3. Finally, calculate the Average Power using the formula above: 

P = Irms^2 * R

Inserting the values from above and solving the equation with the imputed values gives: 

P = 1100^2 * 1.3 = 1,573,000 (watts)

Example Problem #2: 

Using the same process as example problem 1, we first define the variables outlined by the formula. In this case, the values are:

root mean square current (amps) = 140

resistance (ohms) = 40

Entering these values into the formula or calculator above gives us:: 

P = 140^2 * 40 = 19,600 (watts)