Voltage Divider Calculator
Solve any unknown in a two-resistor voltage divider: Vout, Vin, R1, or R2.
V
Ω
Ω
V
Vin ──[R1]──┬──[R2]── GND
│
Vout
Vout
8.0000 V
Current through divider: 4.000 mA (Vin / (R1 + R2) = 12V / 3000Ω)
Voltage Divider Calculator
A voltage divider is a fundamental passive circuit that uses two resistors in series to produce an output voltage that is a fraction of the input. The formula is Vout = Vin × R2 / (R1 + R2). This tool lets you solve for any one of the four variables by entering the other three. It also shows the quiescent current flowing through the divider, which is useful for power budget calculations. All math runs locally in your browser.
Private & free — this tool runs entirely in your browser.
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