Enter the total power (watts) and the total resistance (ohms) into the calculator to determine the Voltage from Power. 

Voltage from Power Formula

The following formula is used to calculate the Voltage from Power. 

V = SQRT ( P*R)


  • Where V is the Voltage from Power (volts)
  • P is the total power (watts) 
  • R is the total resistance (ohms) 

How to Calculate Voltage from Power?

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

Example Problem #1:

  1. First, determine the total power (watts). In this example, the total power (watts) is measured to be 78.
  2. Next, determine the total resistance (ohms). For this problem, the total resistance (ohms) is calculated to be 9.
  3. Finally, calculate the Voltage from Power using the formula above: 

V = SQRT ( P*R)

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

V = SQRT ( 78*9) = 26.49 (volts)

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:

total power (watts) = 90

total resistance (ohms) = 85

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

V = SQRT ( 90*85) = 87.46 (volts)