Peak, RMS & average amplitude
Convert between peak, peak-to-peak, RMS and average values for sine, square and triangle waves.
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Vpp
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Crest factor (peak / RMS)
1.4142
Crest factor in dB
3.01 dB
Form factor (RMS / average)
1.1107
Peak is measured from zero; peak-to-peak spans both half-waves. Meters that read "RMS" but measure the average are only correct for sine waves.
How it works
'Amplitude' can mean several things. The RMS value gives the same heating power as DC and is what audio voltages and levels refer to. The crest factor (peak/RMS) tells how much headroom a signal needs above its RMS level.
Formulas
- sine: RMS = peak / √2, average = 2·peak / π
- square: RMS = average = peak
- triangle: RMS = peak / √3, average = peak / 2
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