📈 Op-Amp Gain Calculator
Pick your amplifier configuration and enter the resistor values to calculate op-amp voltage gain and output voltage.
What this calculator does
Operational amplifier (op-amp) circuits are usually built as either inverting or non-inverting amplifiers, and their voltage gain is set entirely by two resistors: the feedback resistor (Rf) and the input resistor (Rin).
The formulas
For an inverting amplifier, gain = −Rf / Rin (the output is flipped in polarity). For a non-inverting amplifier, gain = 1 + Rf / Rin. This calculator applies whichever formula matches your selected configuration, then multiplies by your input voltage to estimate output voltage, and also converts gain to decibels (dB) using 20 × log10(|gain|).
This assumes an ideal op-amp with very high open-loop gain and negligible input bias current. Real circuits should also respect the op-amp’s supply voltage limits, which will clip the calculated output if it is exceeded.