How to Calculate the Root Mean Square Voltage

There are two different types of electricity: alternating current (AC) and direct current (DC). DC electricity operates at constant voltage and does not have any time variance. AC electricity has a voltage that changes with time, and has a sinusoidal nature. Sometimes it can be useful to quantify the average value of voltage in an AC signal, and this is refered to as the root mean square (RMS) voltage. The RMS voltage of an AC signal can be calculated using a simple formula.

Things You'll Need

• Calculator

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Instructions

1. • 1

     Write down the amplitude of the sinusoidal voltage. The amplitude is the amount that the voltage changes from a peak position to the zero position.

   • 2

     Type the value of the amplitude into the calculator.

   • 3

     Divide the value of the amplitude by the square root of two. The square root of two is 1.414. Press the equals sign. The answer is the value of the root mean square voltage.