Voltage Divider Calculator
Calculate the output voltage of a voltage divider circuit. This tool helps you determine the output voltage based on the input voltage and the values of the two resistors.
Voltage Divider Parameters
Voltage Divider Formula
A voltage divider is a simple circuit that turns a large voltage into a smaller one. Using just two resistors in series, you can create an output voltage that is a fraction of the input voltage.
- Vout = Output Voltage
- Vin = Input Voltage
- R1 = Resistor 1
- R2 = Resistor 2
Standard Resistor Ratios for Common Voltages
| Input Voltage (Vin) | Output Voltage (Vout) | R1 Value | R2 Value |
|---|---|---|---|
| 5V | 3.3V | 1.7kΩ | 3.3kΩ |
| 5V | 2.5V | 1kΩ | 1kΩ |
| 12V | 5V | 7kΩ | 5kΩ |
| 12V | 9V | 1kΩ | 3kΩ |
| 24V | 12V | 1kΩ | 1kΩ |
Frequently Asked Questions
What is a voltage divider used for?
Voltage dividers are used to create a reference voltage, to interface with sensors, and to level-shift signals between circuits that use different voltages.
What is the effect of a load on a voltage divider?
When a load is connected to the output of a voltage divider, it draws current and changes the equivalent resistance of the lower part of the divider. This will lower the output voltage. For this reason, voltage dividers should only be used with high-impedance loads.