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Electrical

Loaded Voltage Divider Calculator

Include a finite load resistance when estimating a resistor-divider output.

Ideal component relationshipsUnits and assumptions explained below
Circuit workbench
Circuit workbench

Keep RMS, peak and DC values distinct.

See the method

Enter circuit values

Runs on your device

Your 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 input voltage, upper resistor, lower resistor, load resistance.
  2. Select Calculate to view the result.
  3. Check the method and assumptions below before using the result.

The method, explained

Replace the lower resistor and load with their parallel equivalent: Rp=Rb×RL/(Rb+RL). Output = Vin×Rp/(Rt+Rp).

A WORKED EXAMPLE

Using input voltage = 12 V, upper resistor = 1000 Ω, lower resistor = 2000 Ω, load resistance = 2000 Ω, the result is 6 V. Change these example inputs to match your task; use the method above to check each step.

Understanding your result

Resistive DC load only; a changing or reactive load requires a different model.

What to keep in mind

Resistive DC load only; a changing or reactive load requires a different model. Ideal-component calculation for study and estimation. It does not select safe wiring, protective devices or component ratings for an installation.

Common questions

How do I use this loaded voltage divider calculator?

Include a finite load resistance when estimating a resistor-divider output. Enter input voltage in V, upper resistor in Ω, lower resistor in Ω, load resistance in Ω. The starting example is editable; use values for the same system or project.

Which assumptions affect this result?

Resistive DC load only; a changing or reactive load requires a different model.

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