Enter the rated power (watts) and the nominal resistance (ohms) into the calculator to determine the Rated Volts. 

Rated Volts Formula

The following formula is used to calculate the Rated Volts. 

Vr = SQRT( Pr * Rn)
  • Where Vr is the Rated Volts (volts)
  • Pr is the rated power (watts) 
  • Rn is the nominal resistance (ohms) 

To calculate the rated voltage, take the square root of the product of the rated power times the nominal resistance.

How to Calculate Rated Volts?

The following two example problems outline how to calculate the Rated Volts.

Example Problem #1:

  1. First, determine the rated power (watts). In this example, the rated power (watts) is measured to be 150.
  2. Next, determine the nominal resistance (ohms). For this problem, the nominal resistance (ohms) is calculated to be 50.
  3. Finally, calculate the Rated Volts using the formula above: 

Vr = SQRT( Pr * Rn)

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

Vr = SQRT( 150 * 50) = 86.602 (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:

rated power (watts) = 60

nominal resistance (ohms) = 70

Entering these values into the formula above gives : 

Vr = SQRT( 60 * 70) = 64.807 (volts)