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Electrical

Voltage Divider Calculator

Find unloaded output voltage from a two-resistor divider.

Ideal component relationshipsUnits and assumptions explained below

Circuit parameters

Runs on your device

CIRCUIT RESULT

Your result

Let’s calculate.

Use the Calculate button to see your result.

Review the method below for assumptions and conventions.

How to use this tool

  1. Enter voltage, first resistance, second resistance.
  2. Select Calculate to view the result.
  3. Check the method and assumptions below before using the result.

The method, explained

Output voltage = input voltage × R2/(R1 + R2).

A WORKED EXAMPLE

Using voltage = 12 V, first resistance = 100 Ω, second resistance = 200 Ω, the result is 8 V. Change these example inputs to match your task; use the method above to check each step.

What to keep in mind

Output is measured across R2. Loading changes the division ratio. Ideal-component calculation for study and estimation. It does not select safe wiring, protective devices or component ratings for an installation.

Common questions

Which inputs does this calculation need?

Find unloaded output voltage from a two-resistor divider. Enter voltage in V, first resistance in Ω, second resistance in Ω. The filled example is editable and is not a saved personal record.

How should I interpret the result?

Output is measured across R2. Loading changes the division ratio. Ideal-component calculation for study and estimation. It does not select safe wiring, protective devices or component ratings for an installation.

Methodology maintained by ClarityKit. How these tools are built and checked.