Voltage Divider Calculator

Vout = Vin · R2/(R1+R2)

How to Use This Calculator

Enter input voltage and resistor values. The output assumes no load (infinite load resistance).

Formula

Vout = Vin · R2/(R1+R2)

If a load RL is present, replace R2 by R2‖RL.

Frequently Asked Questions

Why is my measured Vout lower?

Real loads draw current; use the loaded divider formula considering RL.

What resistor ratio gives 50%?

Choose R1 = R2 for Vout ≈ Vin/2 under no-load conditions.