Instrumentation Amplifier Calculator

Calculate output voltage for a three op-amp instrumentation amplifier.

Circuit Parameters

First Stage (Input Buffer)

Second Stage (Difference Amp)

Results

0.0210 V
Output Voltage
21.0
Total Gain
26.4
Gain (dB)
1.00
Vdiff (mV)

Stage Analysis

First Stage Gain (1 + 2R1/Rg)21.00
Second Stage Gain (R3/R2)1.00
Common Mode Voltage2.5005 V
Typical CMRR80 dB

Gain Formula

G = (1 + 2R1/Rg) * (R3/R2)

Gain is set primarily by Rg. Common ICs like INA128 use this topology.