Step-by-step walkthrough
Use this companion guide beside the interactive calculator to make sure you understand the “why” behind every click. Each section includes the classroom explanation, student-friendly language, and quick practice prompts.
Collect the data points listed below and double-check their units. Keeping an organized “givens” list is one of the fastest ways to reduce math errors and impress exam graders.
Step 1
Choose whether you know three resistors and want the fourth, or you know all four and want the output voltage.
Step 2
Enter the known resistor values in ohms.
Step 3
For the output-voltage mode, also enter the excitation (supply) voltage across the bridge.
Strain gauges, load cells, and RTD temperature sensors all use bridge circuits — a small resistance change from strain or temperature shows up as a measurable voltage the bridge equation converts back into that changing value.
It just means the bridge is unbalanced in the opposite direction — R4's branch is pulling more of the excitation voltage than R2's branch. The sign shows direction, not an error.
