Inverting Amplifier Gain
Inverting configuration
Enter the input voltage, Rin and Rf; gain and output appear live.
Gain & output
How to use this calculator
The inverting amplifier's gain is set entirely by the resistor ratio: Av = −Rf/Rin. The input signal enters through Rin to the inverting terminal; the feedback resistor Rf returns the output to that same terminal. Enter the input voltage, Rin and Rf, and the calculator shows the (negative) voltage gain and the output voltage Vout = Av·Vin.
What it means in a real circuit
For Vin = 1 V, Rin = 10 kΩ, Rf = 100 kΩ, the gain is −10 and the output is −10 V (inverted). The negative sign means the output is 180° out of phase with the input. The inverting configuration has low input impedance (≈ Rin) and high output impedance, making it ideal for summing multiple signals or as a current-to-voltage transimpedance amplifier. Use this to set a precise gain, to invert a signal, or to build a summing node. Keep in mind the output is limited by the op-amp's supply rails — a −10 V output needs at least ±10 V (or a higher) supply to avoid clipping.