Peak-to-peak is a value that represents the difference between the maximum (peak) and minimum (peak) values of a constant waveform such as a sine wave. Also called "peak peak," it is also described as p-p or peak-peak.

It is a numerical value that represents the amplitude of a waveform or signal, and is used to evaluate the waveform of a current or signal. In addition, peak values are used as a criterion for crest factor in particular. It is used in electronics and signal processing measurements, most notably in the evaluation of alternating current (AC).

For a sine wave, the peak-peak value is calculated as the vertical distance between the highest and lowest points. It is also centered at 0 and is twice the maximum positive value. The peak value is one-half of peak-to-peak.