Voltage Divider Calculator

Calculate the output voltage of a resistor-based voltage divider circuit instantly. Enter input voltage, resistor R1, and resistor R2 to get the output voltage, current draw, power dissipation, and load regulation.

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How Voltage Dividers Work

Ohm's Law

Ohm's Law: V = I × R

Formula

Formula: Vout = Vin × (R2 / (R1 + R2))

A voltage divider is a simple circuit that produces an output voltage that is a fraction of its input voltage. It consists of two resistors in series. The output voltage is determined by the ratio of the two resistors. Voltage dividers are commonly used for level shifting, sensor interfacing, and biasing circuits.

Load Effect

When a load is connected to the output, it acts as a parallel resistor with R2, changing the effective resistance and thus the output voltage. For accurate voltage division, the load resistance should be much larger than R2 (typically 10× or more).

Common Applications