Voltage Divider Calculator

The Voltage Divider Calculator helps you calculate output voltage, divider current, resistor power dissipation, and loaded voltage divider behavior using two resistors. This tool also includes reverse calculation mode to help determine resistor values for a desired output voltage.

What is a Voltage Divider?

A voltage divider is a simple resistor network that reduces a higher input voltage into a lower output voltage using two resistors connected in series.

The standard voltage divider formula is:

\( Vout=V_{in}\frac{R_2}{R_1+R_2} \)

Where:

• Vin = Input voltage
• Vout = Output voltage
• R1 and R2 = Divider resistors

Voltage dividers are commonly used in electronics circuits, sensor interfacing, ADC scaling, biasing networks, and reference voltage generation.

Reverse Voltage Divider Calculation

This calculator also supports reverse calculation mode. Instead of calculating output voltage, you can calculate the required resistor value for a desired output voltage.

Example:

• Input voltage = 12V
• Desired output = 5V
• Known resistor = 10kΩ

The calculator automatically determines the required resistor value.

Loaded Voltage Divider Analysis

Most basic calculators ignore loading effects. This tool includes an advanced loaded divider mode using load resistance (RL).

When a load resistor is connected, the effective output voltage changes because R2 becomes parallel with the load resistance.

Loaded divider formula:

\( Req=\frac{R_2R_L}{R_2+R_L} \)

Divider Current & Power Dissipation

The calculator also computes:

• Divider current
• Power dissipation on R1
• Power dissipation on R2

This is useful for selecting proper resistor wattage ratings and reducing power loss in electronic circuits.

Applications

Voltage dividers are widely used in:

• Arduino and ESP32 ADC scaling
• Sensor interfacing
• Audio attenuation circuits
• Voltage reference circuits
• Battery voltage monitoring
• Analog electronics design