Pluck a guitar string and it swings back and forth; the size of that swing — how far it travels from its resting position — is the amplitude. The same idea describes ocean waves, sound volume, AC voltage in your wall outlet, and the brightness flicker of a light bulb. For a sine wave written as y = A sin(Bx), the amplitude is simply the absolute value of A: in y = 5 sin(2x), the amplitude is 5, so the wave's peaks reach 5 above the center line and its troughs dip 5 below it. A common beginner mistake is measuring from trough to peak, which gives twice the amplitude, not the amplitude itself. This calculator handles the quick math behind amplitude problems. Enter your known values into the Variable A and Variable B fields and read the Result — the pattern fits calculations like extracting amplitude from a wave equation's coefficient or from measured maximum and minimum values. Sound engineers, electricians, and physics students all work with amplitude daily, since it is what turns a quiet hum into a loud one.

With the pre-filled defaults — Variable A 10, Variable B 5 — the Amplitude Calculator returns Result 50.0000. Change any input and those results update instantly, so you can see exactly how each number you enter moves the answer.