The two resistor voltage divider is one of the most common and useful circuits used by engineers. The primary purpose of this circuit is to scale down the input voltage to a lower value based on the ratio of the two resistors. This calculator helps determine the output voltage of the divider circuit given the input (or source) voltage and the resistor values. Take note that the output voltage in actual circuits might be different, since resistor tolerance and load resistance (where the output voltage is connected) become factors.