circuits

Voltage Divider Calculator

Solve an unloaded two-resistor voltage divider.

Calculator

Formula

Vout = Vin R₂ / (R₁ + R₂)

Vout — Output voltage: V · mV
Vin — Input voltage: V · mV
R₁ — Top resistance: Ω · kΩ
R₂ — Bottom resistance: Ω · kΩ

Assumptions and limits

Uses the idealized equation shown; verify that it matches your situation.

Example

Worked example

Choose “Load example” in the calculator to restore these inputs and see the complete steps.

Sources

University Physics — OpenStax

Frequently asked questions

Are my inputs uploaded?

No. This calculator runs locally in your browser. Inputs are placed in a URL only when you explicitly copy a share link.

Why are units converted first?

Canonical units prevent scale errors when inputs use mixed units. The result is converted back to your selected output unit afterward.

Does the result replace professional judgment?

No. The result applies only to the stated model and assumptions. Qualified people should review high-risk engineering, medical, or laboratory decisions.