Wheatstone Bridge Calculator

A Wheatstone Bridge is essentially two voltage dividers connected in parallel, with their outputs compared to determine a difference. This configuration is used for precise resistance measurement and sensing applications like temperature or strain measurement.

How it works

The bridge consists of four resistors in a diamond arrangement:

• Static divider: R1 (top-left) and R3 (bottom-left)
• Variable divider: R2 (top-right) and R4 (bottom-right)

The output voltage is the difference between the two divider midpoints:

Vout = Vvariable - Vstatic

Where:

• Vstatic = Vin x R3 / (R1 + R3)
• Vvariable = Vin x R4 / (R2 + R4)

When R1/R3 = R2/R4, the bridge is balanced and Vout is zero. Any change in one resistor (for example an NTC thermistor responding to temperature) creates a measurable differential voltage.

Applications

• Temperature measurement using NTC or platinum RTD sensors
• Strain gauge measurement
• Pressure sensing
• Any application requiring precise detection of small resistance changes