AC foundations
Peak-to-peak voltage
- where
- peak-to-peak voltage (V)
- peak voltage (V)
Explain this equation
Works out peak-to-peak voltage from peak voltage. Useful when comparing with scope readings.
Vₚₚ is the voltage from the top of the positive peak to the bottom of the negative one. Vₚ is the peak measured from zero.
A symmetrical waveform swings the same amount above and below zero, so the full swing is twice the peak.
Sense check: 100 V peak is 200 V peak-to-peak. 230 V mains has a peak of about 325 V, so about 650 V peak-to-peak.
Watch out: start from the peak, not the RMS. Doubling 230 V gives 460 V, which is wrong for peak-to-peak.
Peak-to-peak measures from the most negative point to the most positive. For a symmetrical waveform those magnitudes are equal.
For unequal peaks use Vmax − Vmin instead. Do not double an RMS reading unless you also apply the appropriate peak conversion.
Enter your values to see the result.
Common mistake
Doubling RMS and calling the result peak-to-peak.
Limits
Equal positive and negative peak magnitudes for the 2Vₚ form.
Sources
The tools calculate the displayed equation. They do not automatically choose cable sizes, approve installations, supply current regulatory tables, certify equipment or replace inspection and testing.