Enter the source voltage and the resistance of two different resistors to calculate the output voltage of a voltage divider.

Voltage Divider Formula

The following formula is used in voltage dividers.

voltage divider formula
  • Where V out is the output voltage
  • V in is the input voltage
  • R1 is the value of resistor one in resistance
  • R2 is the value of resistor two in resistance

The voltage is measure in volts and the resistance is measure in ohms.

Voltage Divider Definition

A voltage divider is a system or two more resistors that divides an input voltage into a reduced output voltage.

How to calculate a voltage

  1. First, determine the two resistances.

    This is calculating the voltage out in a voltage divider, so there should be two different resistances.

  2. Next, measure the voltage going into the voltage divider.

    Using a voltmeter or similar device, measure the voltage entering the divider.

  3. Calculate the output voltage.

    Enter the information from steps 1 and 2 into the calculator or formula above.


What is a voltage divider?

A voltage divider is a device that consists of two or more resistors that reduce the output voltage entering the device.

What does a voltage divider do?

A voltage divider reduces the output voltage given an input voltage.