Series Capacitance Calculator
µF
µF
µF
Total Capacitance5.9977 µF
Capacitors3
The Series Capacitance Calculator works out the combined capacitance of capacitors connected end to end in a single chain. Series capacitors behave the opposite of series resistors: the same charge sits on every capacitor, the voltages add, and the resulting capacitance is smaller than the lowest member of the chain. Enter each capacitance value and the tool sums the reciprocals to give the equivalent series capacitance.
Formula
1 / Ct = 1/C1 + 1/C2 + … + 1/Cn
- Ct
- Equivalent series capacitance
- C1…Cn
- Each individual capacitor in the series chain
How it works
- Enter each capacitor value in microfarads, adding rows so the chain matches the number of series capacitors in your circuit.
- The calculator adds the reciprocal of every capacitance, then takes the reciprocal of that sum to find the equivalent series capacitance.
- Because reciprocals are summed, the answer is always lower than the smallest capacitor, and longer chains shrink it further.
Worked example
A 6 µF capacitor in series with a 3 µF capacitor.
- Sum of reciprocals = 1/6 + 1/3 = 0.16667 + 0.33333 = 0.5 per µF.
- Equivalent capacitance = 1 ÷ 0.5 = 2 µF.
The two capacitors in series behave as a single 2 µF capacitor.
Frequently asked questions
- Why does series capacitance get smaller, unlike resistors?
- In series the same charge sits on each capacitor while their voltages add up. For a fixed charge a larger total voltage means a smaller overall capacitance, so the combination is less than any single capacitor.
- What happens with two equal capacitors in series?
- Two equal capacitors in series give exactly half the value of one. Two 10 µF capacitors in series equal 5 µF, and N equal capacitors give C divided by N.
- Why connect capacitors in series at all?
- Series connection raises the voltage rating because the applied voltage divides across the capacitors. It is a common way to handle voltages above a single capacitor rating, at the cost of lower total capacitance.
- Does the unit I enter matter?
- No, as long as every capacitor uses the same unit. Enter all values in microfarads and the equivalent capacitance is returned in microfarads as well.