Voltage Divider Calculator

Calculate output voltage, current, and power dissipation for resistor divider circuits.

Component Values

V

Results

Output Voltage (Vout)6.000 V
Voltage Ratio50.00 %
Current600.0 µA
Power in R13.600 mW
Power in R23.600 mW
12 V10 kΩ6.000 V10 kΩ+

Voltage Divider

How does a Voltage Divider work?

A voltage divider uses two series resistors to produce an output voltage that is a fraction of the input. The output is taken at the junction between R1 and R2. It is one of the most fundamental circuits in electronics.

Output Voltage (Vout)

Vout = Vin × R2 / (R1 + R2)

Current

I = Vin / (R1 + R2)

Key Points

  • Vout is always less than Vin (for positive R1, R2)
  • The ratio depends only on the resistor values, not absolute values
  • Load resistance in parallel with R2 changes the output voltage
  • Higher resistance = less current = less power dissipation

Applications

  • Level shifting (e.g. 5V to 3.3V logic)
  • Biasing transistor base voltage
  • ADC reference voltage generation
  • Potentiometers and sensor interfaces