Voltage Divider Calculator

Calculate output voltage from series resistors

Circuit Diagram

Vin 12V R1 1kΩ Vout 6V R2 1kΩ

Calculator

V
Ω
Ω
6.0
V
Output Voltage
50
%
Voltage Ratio

Results

Output Voltage (Vout): 6.0000 V
Voltage Division Ratio: 0.5000 (50.00%)
Current (no load): 6.00 mA
Attenuation: 6.00 V
Power (R1): 36.00 mW
Power (R2): 36.00 mW
Total Power: 72.00 mW

Formula & Calculation

FORMULA:

Vout = Vin × (R2 / (R1 + R2))

CALCULATION:

Vout = 12V × (1000Ω ÷ (1000Ω + 1000Ω))

Vout = 12V × 0.5000

Vout = 6.00V

Quick Presets

What is a Voltage Divider?

A voltage divider is a simple circuit that converts a large voltage into a smaller one using two resistors in series. The output voltage is a fraction of the input voltage, determined by the ratio of the resistances.

The Formula:

Vout = Vin × (R2 / (R1 + R2))

How It Works:

Current flows from the voltage source (Vin) through R1, then through R2 to ground. Since the same current flows through both resistors (they're in series), the voltage drop across each resistor is proportional to its resistance. The output is taken from the junction between R1 and R2.

Key Points:

• The output voltage is always less than the input voltage

• Larger R2 relative to R1 gives higher output voltage

• Total resistance affects current draw and power dissipation

• This circuit assumes no load (infinite load impedance)

Common Applications:

• Level shifting for sensors and microcontrollers

• Creating reference voltages

• Voltage measurement and monitoring

• Signal conditioning