Capacitors in Series & Parallel Calculator
Find the equivalent capacitance of up to four capacitors in parallel and in series, and the energy stored at a voltage.
Capacitors add up the opposite way to resistors — here is the total.
How the capacitors in series & parallel calculator works
Capacitors behave the reverse of resistors: in parallel their plate areas effectively add, so capacitances add (C = C₁ + C₂ + …); in series the charge is shared and the reciprocals add (1 ÷ C = 1 ÷ C₁ + 1 ÷ C₂ + …). Two equal capacitors in series give half of one.
The energy stored is ½ C V²; enter a voltage in Detailed mode to see it for the parallel combination. Leave unused slots at 0.
Formula: parallel: C = C₁ + C₂ + … · series: 1 ÷ C = 1 ÷ C₁ + 1 ÷ C₂ + … · E = ½ C V²
Worked examples
| Inputs | Parallel total | Note |
|---|---|---|
| 10 µF and 22 µF | 32 µF | parallel 32, series 6.875 |
| Two 100 µF | 200 µF | series gives exactly half |
| 1, 2, 3 and 4 µF | 10 µF | parallel 10, series 0.48 |
FAQFrequently asked questions
Why do capacitors add in parallel?
Connecting them side by side is like enlarging the plates — more area stores more charge at the same voltage.
Why put capacitors in series at all?
To raize the voltage rating: each capacitor sees only part of the total voltage. The capacitance drops, so it is a trade.
How much energy does a capacitor store?
½ C V². A 32 µF set at 12 V holds 2.3 mJ — tiny beside a battery, but delivered fast.
What are the unit prefixes?
µF (microfarad, 10⁻⁶), nF (nano, 10⁻⁹), pF (pico, 10⁻¹²). Convert everything to one unit before adding; the calculator works in µF.
Where these figures come from
- NIST — CODATA 2018 fundamental physical constants — G, g₀, R, c
- NIST Special Publication 811 — Guide for the use of the International System of Units — unit conversions
- The Engineering ToolBox — material properties — specific heats, expansion coefficients, densities
- National Institute of Standards and Technology — the US measurement authority
Last checked: September 2026. Constants are the CODATA 2018 values; formulas are the standard textbook forms.