ProcirelA voltage divider uses two series resistors to produce an output voltage that is a fraction of the input voltage. It is one of the most common circuits in electronics, used for sensor signal conditioning, ADC input scaling, transistor biasing, and creating reference voltages.
How to use this calculator
Step-by-Step Instructions
1. **Enter the input voltage** This is the voltage source connected to the top of your divider (e.g., 12V, 5V, 3.3V).
2. **Enter R1 (top resistor)** This is the resistor connected between the input voltage and the output (center) node. Enter the value in Ohms.
3. **Enter R2 (bottom resistor)** This is the resistor connected between the output node and ground. Enter the value in Ohms.
4. **Click Calculate** The output voltage, divider current, power dissipation, and voltage ratio are displayed.
Worked Example
You need to scale a **12V signal to 3.3V** for an Arduino ADC input:
Using R1 = 27kΩ, R2 = 10kΩ Vout = 12 × 10000 ÷ 37000 = **3.24V**(close to 3.3V)