What is a Voltage Divider?

A voltage divider is a fundamental linear circuit that produces an output voltage (V_out) which is a fraction of its input voltage (V_in). It is created by distributing the input voltage among the components of the divider. In its simplest form, it consists of two resistors connected in series. This tool acts as a Voltage Divider Calculator Online to help engineers, hobbyists, and students quickly determine the exact output without manual arithmetic.

The Voltage Divider Formula

The calculation is based on Ohm's Law and the principles of series circuits. The mathematical formula used by this calculator is:

Where R1 is the resistor connected to the input source, and R2 is the resistor connected to the ground. The output is taken from the junction between R1 and R2.

How to Use This Calculator

Using our online tool is straightforward:

• Step 1: Enter the Input Voltage (V_in) in Volts.
• Step 2: Enter the resistance value for R1 and select the appropriate unit (Ohms, kOhms, or MOhms).
• Step 3: Enter the resistance value for R2 and select its unit.
• Step 4: The Output Voltage (V_out) will update instantly in the result box.

Common Applications

Voltage dividers are ubiquitous in electronics. They are commonly used to create reference voltages, to measure high voltages using a microcontroller (like an Arduino or ESP32) by scaling the voltage down to a safe range (0-3.3V or 0-5V), and in sensor circuits like LDRs (Light Dependent Resistors) or thermistors.

Frequently Asked Questions

Does the load affect the output voltage?
Yes. If you connect a load to the output of a voltage divider, that load acts as a resistor in parallel with R2, which changes the equivalent resistance and lowers the output voltage. For precision, the load resistance should be significantly higher than R2.

Can I use this for AC voltage?
Yes, the resistive voltage divider formula works for AC voltages as well, provided the components are purely resistive and frequency effects are negligible.