Inverting Amplifier Calculator
Enter the input voltage, input resistor, and feedback resistor to instantly calculate the closed-loop gain and output voltage of an op-amp inverting amplifier.
Op-Amp Inverting Amplifier
V
Enter values on the left and click Calculate to see the results.
Closed-Loop Voltage Gain
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V/V
Formula: Gain = −(Rf / Rin)
Output Voltage — Vout
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V
Formula: Vout = Gain × Vin
Calculation Breakdown
Input Voltage (Vin)
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Input Resistor (Rin)
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Feedback Resistor (Rf)
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Gain (Rf / Rin)
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Closed-Loop Gain
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Output Voltage (Vout)
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Summary
Enter the input voltage, input resistor, and feedback resistor to instantly calculate the closed-loop gain and output voltage of an op-amp inverting amplifier.
How it works
- Enter the input voltage (Vin) in volts.
- Enter the input resistor value (Rin) in ohms, kilohms, or megaohms.
- Enter the feedback resistor value (Rf) in ohms, kilohms, or megaohms.
- The calculator applies Gain = -(Rf / Rin) to find the closed-loop gain.
- Output voltage is computed as Vout = Gain × Vin.
- Results update instantly as you type.
Use cases
- Design signal conditioning circuits with a specific gain target.
- Verify resistor selections for audio amplifier stages.
- Quickly check gain and output swing before building a prototype.
- Teach op-amp inverting amplifier theory with live feedback.
- Size feedback resistors for instrumentation amplifier front ends.
- Confirm polarity inversion and magnitude for control system loops.
- Estimate output voltage headroom against supply rails.
- Convert sensor output levels to ADC input ranges.
Frequently Asked Questions
Last updated: 2026-07-01 ·
Reviewed by Nham Vu