Voltage Divider Calculator

Calculate output voltage, resistor values, or input voltage for a resistor voltage divider circuit.

Solve For

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Input Values

Enter the known values below

Circuit Diagram

VinR1VoutR2GNDI ↓

Quick Guide

Core Formula:

Vout = Vin × R2 / (R1 + R2)

Common Uses:

  • Level shifting (e.g. 5V to 3.3V for microcontrollers)
  • Sensor signal conditioning
  • ADC reference voltage scaling
  • Bias voltage generation
  • Feedback networks in regulators

Tips:

  • Keep total resistance high to minimize current draw
  • Use 1% tolerance resistors for precision applications
  • Account for load impedance — it acts as a parallel resistance with R2
  • Unloaded voltage dividers are not suitable for powering loads