Capacitor calculator
Calculate the total capacitance of a series or parallel connection, plus the charge and energy of a charged capacitor.
Mode
Parallel connection: 200 µF
Series connection: 50 µF
How the calculator works
In a parallel connection capacitances add up: C = C₁ + C₂ + …. In series the reciprocal sum applies: 1/C = 1/C₁ + 1/C₂ + … – exactly the opposite of resistors. Enter any number of values in pF, nF or µF and the calculator shows both results at once.
In charge-and-energy mode it calculates Q = C × U and E = ½ × C × U². For example, a 100 µF capacitor charged to 12 V carries a charge of 1.2 mC and an energy of 7.2 mJ.
Worked examples
| Input | Result |
|---|---|
| 2× 100 µF in parallel | 200 µF |
| 2× 100 µF in series | 50 µF |
| 10 µF + 22 µF in parallel | 32 µF |
| 100 µF charged to 12 V | Q = 1.2 mC; E = 7.2 mJ |
Frequently asked questions
Why do capacitances add up the opposite way to resistances?
A parallel connection increases the electrode area, so capacitances add. A series connection increases the distance between electrodes, so the total capacitance is smaller than the smallest value.
How do I convert µF, nF and pF?
1 µF = 1,000 nF = 1,000,000 pF. A capacitor marked 104 is 10 × 10⁴ pF = 100 nF.
What should I watch out for with electrolytic capacitors?
They are polarised – reverse connection destroys them – and have a rated voltage that must not be exceeded. In series connections the voltage divides unevenly according to the capacitances.
How much energy does a capacitor store?
E = ½ × C × U² – energy grows with the square of the voltage. A camera flash with 1,000 µF at 300 V holds 45 J, which is why it can be dangerous even after the device is switched off.
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Last updated: 16 July 2026