Convert RMS to peak voltage or current, or peak and peak-to-peak back to RMS, for sine, square, triangle or sawtooth waves or a custom crest factor.

Convert an effective RMS amplitude to peak and peak-to-peak amplitude.

Presets assume ideal zero-centered waveforms. For other shapes, choose Custom and enter the measured crest factor.

Optional settings

Related Calculators

RMS to Peak Formula

The following formula converts RMS to peak for a pure, zero-centered sine wave. Other supported waveform shapes use their own crest factor.

PV = RMS × √2

Variables:

  • PV is the peak value (volts or amps)
  • RMS is the root mean square value (volts or amps)

For a pure, zero-centered sine wave, multiply RMS by the square root of 2. More generally, peak = RMS × crest factor. Peak-to-peak is twice the peak only when positive and negative extrema are symmetric; a custom crest factor alone does not establish that symmetry.

Sine Wave Conversion Table: RMS to Peak and Peak-to-Peak (Volts)
RMS (V) Peak (V) Peak-to-Peak (V)
0.10.1410.283
0.20.2830.566
0.50.7071.414
11.4142.828
1.52.1214.243
22.8285.657
2.53.5367.071
3.34.6679.334
57.07114.142
6.38.91017.819
912.72825.456
1014.14228.284
1216.97133.941
1521.21342.426
2433.94167.882
4867.882135.765
6084.853169.706
120169.706339.411
230325.269650.538
240339.411678.823
Assumes a pure sine wave. Formulas: Peak = RMS × √2; Peak-to-Peak = 2 × Peak = 2√2 × RMS. √2 ≈ 1.414.

What is RMS?

RMS stands for root mean square: the square root of the average squared instantaneous values over the interval of interest. An RMS voltage across a fixed resistor produces the same average heating as an equal DC voltage; the analogous relationship applies to current. RMS voltage or current alone does not determine real power in an arbitrary AC load; phase and waveform relationships can also matter.

How to Calculate Peak Value from RMS?

The following steps outline how to calculate the Peak Value from RMS.

  1. First, determine the RMS value (RMS) in volts or amps.
  2. Next, select the waveform. For a pure zero-centered sine wave use PV = RMS × √2; for another supported waveform use its stated crest factor.
  3. Finally, calculate the Peak Value (PV) in volts or amps.
  4. After inserting the RMS value and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variable as an example problem to test your knowledge.

RMS value (RMS) = 10 volts