Voltage Divider Calculator

Calculate any value in a 2-resistor voltage divider (R1, R2, Vin, Vout).

Enter any 3 values to find the 4th. Vout is the voltage across R2.

Input Voltage Vin (V)

V

Output Voltage Vout (V)

V

Resistor R1 (Ω)

Ω

Resistor R2 (Ω)

Ω

Result

—

Formulas

Vout = Vin × R2 / (R1 + R2)
R1 = R2 × (Vin / Vout − 1)
R2 = R1 / (Vin / Vout − 1)
Vin = Vout × (R1 + R2) / R2