Resistance

The total resistance of a parallel circuit will always be less than the total resistance of any branch within the circuit and adding additional branches will always decrease the total resistance of the circuit.

To calculate the total resistance of a parallel circuit, take the sum of the reciprocal of the resistance for each component in the circuit and that equals the reciprocal of the total resistance. Sounds confusing? It really isn't. Here is the formula:

This formula will go out to however many resistance values are needed. In the example circuit, there are two resistors with values to 220 ohms and 330 ohms. Therefore, to calculate the resistance of the circuit we would take the reciprocal of 1/220 + 1/330, which would equal 132 ohms.

Rather than trying to calculate the resistance of a parallel circuit by hand, there are plenty of online calculators that you can use.