Percent of Modulation Formula and Calculator

The percentage % of modulation is an indicator of the extent to which it is modulated.

Here is a picture of an unmodulated sine wave.

By comparison here is a picture of an Amplitude Modulated sine wave.

Formula

The percent modulation is given by

%_M = ((V_MAX-V_MIN)/(V_MAX+V_MIN)) * 100

Calculator

Example

In the following example, V_MAX = 2.5, V_MIN = -0.5. Using these numbers in the calculator gives 150% modulation. This is an example of an overmodulated signal.

If V_MAX = V_MIN, the sine wave is not modulated and the percentage modulation is 0.