RMS Voltage Calculator


What is the rms value of voltage?

The RMS value of a fluctuating voltage or current is its effective value. The corresponding steady DC constant value produces the same effect.

How does RMS voltage become calculated?

For a sinusoidal waveform, the RMS voltage VRMS is calculated by multiplying the peak voltage value by 0.7071, which is equal to one divided by the square root of two.

What is the difference between RMS and peak voltage?

Peak values can be computed using the above formula’s RMS values, which means  VP = VRMS × √2, provided the source is a pure sine wave. Thus, the peak value of the mains voltage is approximately 120 × √2, or approximately 170 volts. The peak-to-peak voltage is around 340 volts.


RMS Value determined from Peak Value: VP

VRMS = 0.7071 x VP

RMS Value determined from Peak to Peak Value: VPP

VRMS = 0.35355 x VPP

RMS Value determined from Average Voltage Value: VAV

VRMS = 1.11 x VAV

Click here for more Electrical Calculators