Wheatstone Bridge Calculator

At balance: R1/R2 = R3/Rx ⇒ Rx = R3·R2/R1

How to Use This Calculator

Enter R1, R2, and R3 for a Wheatstone bridge in balance (zero galvanometer current). Click Calculate to get Rx.

Formula

At balance: R1/R2 = R3/Rx

Rx = (R3 · R2) / R1

Frequently Asked Questions

Do I need the supply voltage?

No. At balance, the ratio relation is independent of supply voltage.

What if the bridge is not balanced?

Adjust a known resistor until the galvanometer reads zero, then apply the formula.