What is a Wheatstone bridge?

Classic four-arm circuit for precision resistance measurement. At null balance, Rx = R3 × R2 / R1. Used in strain gauges, pressure sensors, temperature measurement.

What is null balance?

Condition where voltage between bridge midpoints = 0. Detector reads zero. Indicates Rx = R3 × R2 / R1. Null balance is more accurate than voltage measurement.

How do I solve for unknown resistance?

Adjust known resistor R2 until detector shows null. Then Rx = R3 × (R2/R1). Used in precision resistance measurement and fault finding.

What is bridge sensitivity?

Change in output voltage per unit change in unknown resistance. Higher sensitivity = better for detecting small changes.

What is bridge imbalance?

When Rx ≠ R3 × R2/R1, bridge output ≠ 0. Output voltage indicates degree of imbalance. Used in sensor readout.

Engineering

Wheatstone Bridge Calculator

Calculate null balance and unknown resistance in Wheatstone bridge circuits.

R1 (Ω)

R2 (Ω)

R3 (Ω)

Null Balance Result

Rx (Unknown)—

Balance Ratio—

Frequently Asked Questions

Classic four-arm circuit for precision resistance measurement. At null balance, Rx = R3 × R2 / R1. Used in strain gauges, pressure sensors, temperature measurement.
Condition where voltage between bridge midpoints = 0. Detector reads zero. Indicates Rx = R3 × R2 / R1. Null balance is more accurate than voltage measurement.
Adjust known resistor R2 until detector shows null. Then Rx = R3 × (R2/R1). Used in precision resistance measurement and fault finding.
Change in output voltage per unit change in unknown resistance. Higher sensitivity = better for detecting small changes.
When Rx ≠ R3 × R2/R1, bridge output ≠ 0. Output voltage indicates degree of imbalance. Used in sensor readout.