Use this electronics calculation for a first-pass component, converter, signal, motor, or sensor estimate when the stated operating conditions and units match the device data.

Feedback resistance (kΩ)

Required number input.

Input 1 voltage (V)

Required number input.

Input 1 resistance (kΩ)

Required number input.

Input 2 voltage (V)

Required number input.

Input 2 resistance (kΩ)

Required number input.

Compute the inverting two-input summing amplifier output as -(Rf x (V1/R1 + V2/R2)). The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Summing output (V)

The resulting summing output returned as a number.

• Amplifier gain and rejection calculations are small-signal approximations unless the operating point is checked. Gain-bandwidth, slew rate, input and output range, stability, noise, offset, bias current, loading, and frequency-dependent CMRR can limit the result.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Check the result against the current datasheet and worst-case operating corners, then verify the circuit or measurement with simulation and bench testing where failure matters.

• Voltage Divider Calculator

  Compute the divided output voltage across R2 of a two-resistor series divider: Vout = Vin * R2 / (R1 + R2).

• Chopper Amplifier Offset

  Input-referred residual DC offset of a chopper amplifier from its zero-input output offset and closed-loop voltage gain.

• Current Shunt Amplifier Gain

  Voltage gain of a current-shunt amplifier from output swing and measured shunt input swing.