Voltage Divider Calculator
This bidirectional tool solves for any parameter in a voltage divider circuit (Vin, R1, R2, or Vout). It supports unit selection (Ω, kΩ, MΩ) for easier input.
Pro Feature: It calculates the Power Dissipation (to prevent burning components) and suggests the Nearest Standard Resistor (E24) for real-world builds.
Circuit Parameters
Enter Any 3Calculation Status
Waiting for input…
Live Circuit Analysis
VisualComponent Analysis
Key Equations
Voltage Output
Vout = Vin × ( R2 / (R1 + R2) )
Input Voltage
Vin = Vout × ( (R1 + R2) / R2 )
Find R1
R1 = R2 × ( (Vin / Vout) − 1 )
Find R2
R2 = R1 / ( (Vin / Vout) − 1 )
How to Use This Calculator
Design a voltage divider in 3 simple steps.
Enter 3 Values
Fill in any three known parameters. For example, to find the Output Voltage, enter Vin, R1, and R2.
Set Units
Use the dropdown menu to select Ω, kΩ, or MΩ for resistors. This saves you from typing extra zeros.
Check Power & Standard Values
Review the Component Analysis box. Ensure the Power Dissipation is less than your resistor’s rating (usually 0.25W) and note the nearest E24 standard value for purchasing.