Series and Parallel Calculator
List resistor or capacitor values separated by commas or new lines to get the series and parallel equivalents together.
Formulas
Resistors in series add: R = R1 + R2 + …. In parallel: 1/R = 1/R1 + 1/R2 + …. Capacitors work the other way around: they add in parallel and combine as reciprocals in series.
Frequently asked questions
Is there a quick way to combine two resistors in parallel?
Use R1 × R2 / (R1 + R2). Two equal resistors in parallel give half the value, so two 10 kΩ resistors make 5 kΩ.
Why put capacitors in series?
The total capacitance drops, but the combination can withstand a higher voltage. Capacitance tolerances can split the voltage unevenly, so at high voltage add equal balancing resistors across each capacitor.