How to use the wheatstone bridge calculator
Find the unknown resistance of a balanced bridge. Enter r1, r2, r3 in the fields above; the unknown r4 is computed instantly and plotted on the chart so you can see how the answer changes.
Formula
Variables
- R1 — R1 (Ω)
- R2 — R2 (Ω)
- R3 — R3 (Ω)
Worked example
With r1 = 100 Ω, r2 = 200 Ω, r3 = 300 Ω, the calculator gives unknown r4 ≈ 600 Ω.
Frequently asked questions
What is the formula for the wheatstone bridge calculation?
Unknown R4 (Ω) = R2 × R3 / R1. Here R1 is r1 (Ω), R2 is r2 (Ω), R3 is r3 (Ω).
What inputs do I need for the wheatstone bridge calculator?
You need r1 in Ω, r2 in Ω, r3 in Ω. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use this calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.