Op-Amp Gain Calculator
Get the voltage gain, gain in decibels and output voltage of an inverting or non-inverting amplifier.
Input and output
Formulas
Non-inverting amplifier: Av = 1 + Rf/Rg. Inverting amplifier: Av = −Rf/Rin. Gain in decibels is 20·log10|Av|. These assume an ideal op-amp, so a real output clips a little below the supply voltage.
Frequently asked questions
Can a non-inverting amplifier have a gain below 1?
No. Its gain is 1 + Rf/Rg, so the minimum is 1. With Rf shorted and Rg removed it becomes a unity-gain voltage follower (buffer). To attenuate, add a divider in front or use an inverting amplifier.
What if the calculated output is higher than the supply?
The output clips near the supply rail and the waveform distorts. Unless the op-amp is rail-to-rail, expect clipping 1 to 2 V below the supply and leave headroom.