Formula
Unloaded Vout = Vin × R2 ÷ (R1 + R2). A load is combined in parallel with R2 before recalculation.
ELECTRONICS
Voltage Divider Calculator
Calculate loaded or unloaded output voltage for a two-resistor divider.
CALCULATOR GUIDE
How to use the Voltage Divider Calculator
Calculate unloaded or loaded voltage-divider output, divider current and resistor power.
Worked example
Two equal 1 kΩ resistors divide 12 V to 6 V when no load is connected.
Assumptions and limits
A voltage divider is not a regulated power supply. Connected loads and resistor tolerances change output voltage.
Frequently asked questions
Why does a load reduce output voltage?
The load sits in parallel with the lower resistor, reducing its effective resistance.
Can a divider power a device?
Usually only very light loads. Use a regulator or buffer when stable voltage or meaningful current is required.
How this calculator works
Enter your known values and select Calculate result. Review units and inputs before relying on the planning estimate.
Actual quantities, prices and requirements can vary. Confirm critical work with a supplier or qualified professional.