Resistor voltage division calculation

Input voltageVin: V
Series resistanceRa: Ω
Parallel resistanceRb: Ω
Output voltageVout: V

In a series circuit, the currents on each resistor are equal, and the sum of the voltages across each resistor is equal to the total circuit voltage. It can be seen that the voltage on each resistor is less than the total circuit voltage, so the series resistors divide the voltage.