Understanding the Voltage Divider
A voltage divider is a fundamental passive circuit used to reduce a higher voltage to a lower one. It consists of an input voltage Vin, two resistors (R1 and R2) in series, and an output voltage (Vout) taken from the junction between them.The Voltage Divider Formula
The relationship between these components is defined by the following equation:
Vout = Vin × (R2 / (R1 + R2))How to Use This Calculator
Whether you are trying to find the output voltage or determine the specific resistor values needed for your project, this tool simplifies the process:
- Solve for Vout: Enter your input voltage and both resistor values to see the resulting output.
- Determine Resistors: Switch modes to calculate the required value for R1 or R2 based on a target output voltage.
- Real-time Analysis: The calculator also provides the total current (I) and power consumption of the circuit.
Simply enter your known values into the fields below to begin.
The output voltage is a fraction of the input voltage, determined by the ratio of R2 to the total series resistance (R1 + R2). Enter any three known values above and the calculator will solve for the fourth.
What is a Voltage Divider?
A simple circuit using two series resistors to produce an output voltage that is a fraction of the input voltage.
Common Uses
Level shifting, sensor interfaces, biasing transistors, reading resistive sensors with microcontrollers, and creating reference voltages.
Important Notes
Output voltage assumes no load. In real circuits, load resistance and resistor tolerances will affect the actual output.
Rule of Thumb
When R1 = R2, the output voltage is exactly half of the input voltage. Increasing R2 relative to R1 raises Vout.