Voltage Divider Calculator
Calculate the output voltage of a resistive voltage divider. Enter any two resistor values and the input voltage to find Vout — or work backwards to find the resistor pair for your target output voltage. Includes standard E12/E24 value matching.
Volts (V)
Ohms (Ω)
Ohms (Ω)
Output Voltage (Vout)—
Current Through Divider—
Power Dissipated (R1 + R2)—
Divider Ratio (Vout/Vin)—
Voltage Divider Formula
Vout = Vin × R2 ÷ (R1 + R2)
The voltage divider is one of the most fundamental circuits in electronics. It uses two resistors in series to produce an output voltage that is a fraction of the input. Common uses include:
- Level shifting — converting 5V signals to 3.3V for microcontrollers
- Reference voltages — creating a stable reference for comparators and ADCs
- Sensor circuits — reading resistive sensors (LDRs, thermistors) with an ADC
- Biasing — setting the operating point of transistors and op-amps