Peak Voltage Calculator

Calculate the peak voltage using either the peak-to-peak or the RMS voltage and the calculator below.

Convert Peak-to-Peak Voltage to Peak Voltage

Convert RMS Voltage to Peak Voltage

Peak Voltage Results:

  volts


Do you want to calculate peak-to-peak voltage or RMS voltage?

How to Calculate Peak Voltage

The peak voltage is the distance from 0 volts to the peak of the AC sine waveform, or the highest point of the waveform. Peak voltage can be found if you know the peak-to-peak voltage or the RMS voltage.

Voltage waveform with peak voltage, peak-to-peak voltage, and RMS voltage marked.
Diagram showing the peak voltage, peak-to-peak voltage, and RMS voltage on an AC waveform.

Peak-to-Peak Voltage to Peak Voltage Formula

If you know the peak-to-peak voltage then you can find the peak voltage using this formula where VP-P is the peak-to-peak voltage.

VP = VP-P2

Thus, peak voltage is equal to peak-to-peak voltage divided by two.

For example, find the peak voltage given a peak-to-peak voltage of 240 V.

VP = 240 V2
VP = 120 V

RMS Voltage to Peak Voltage Formula

If the RMS voltage is known then the peak voltage can be found using this formula where VRMS is the RMS voltage.

VP = √2 × VRMS

Thus, peak voltage is equal to the square root of two times the RMS voltage.

For example, find the peak voltage if the RMS voltage is 85 V.

VP = √2 × 85 V
VP = 120.208 V