Total Capacitance in Parallel & Series
Updated October 2026
Capacitors combine in exactly the opposite way to resistors, which trips people up constantly. In parallel, capacitances simply add together — the total is larger than any single capacitor. In series, they combine by the reciprocal formula, so the total is smaller than the smallest. Enter your capacitor values, pick the configuration, and this calculator gives the total while showing the other arrangement for comparison.
The reason is physical: putting capacitors in parallel effectively increases the total plate area available to store charge, and more plate area means more capacitance. This is the mirror image of how resistors behave, so if you've internalized the resistor rules, just flip them for capacitors.
For capacitors in parallel, the total is C₁ + C₂ + C₃ + … — you just add them up. Three capacitors of 10, 22, and 47 µF in parallel give 79 µF. This is the most common way to increase capacitance: combine several capacitors to reach a larger value than any single one you have, which is useful for smoothing power supplies and bulk energy storage.
In series, capacitors follow 1/C_total = 1/C₁ + 1/C₂ + …, the same reciprocal math that resistors use in parallel. The total is always less than the smallest capacitor in the chain. Series combinations are less common but matter when you need to divide voltage across capacitors or achieve a small, precise capacitance. This calculator's series mode handles it directly.
It's worth stating the symmetry plainly because it's the key to never getting confused: capacitors in parallel add (like resistors in series), and capacitors in series use reciprocals (like resistors in parallel). If you ever blank on which rule applies, recall that parallel capacitors share more plate area and therefore store more — addition. For the resistor side of this symmetry, see the parallel resistor calculator.
Consider three capacitors of 100 µF, 220 µF, and 330 µF. The right calculation depends entirely on how they are wired, and working both arrangements by hand shows why the two cases are mirror images. In parallel, capacitors simply add: C = 100 + 220 + 330 = 650 µF. That is the whole calculation — no reciprocals, no inversion. The total is larger than any single capacitor, because wiring capacitors in parallel effectively combines their plate areas, and more plate area stores more charge at a given voltage.
The same three capacitors in series behave completely differently. Here the reciprocal formula applies, identical in form to resistors in parallel: 1/C = 1/100 + 1/220 + 1/330. Using a common denominator and adding gives approximately 0.01 + 0.004545 + 0.003030 = 0.017576 (in units of 1/µF). Inverting that sum yields C ≈ 56.9 µF. Just as with parallel resistors, the final reciprocal step is essential and easy to forget — the sum 0.017576 is the reciprocal of the capacitance, not the capacitance itself. The series total, about 56.9 µF, is smaller than the smallest capacitor in the chain, which is always the case for series capacitors and serves as a quick sanity check.
Putting the two results side by side makes the symmetry concrete: the very same three capacitors give 650 µF in parallel but only about 57 µF in series — more than a tenfold difference driven purely by wiring. This is the opposite of resistors, where series increases resistance and parallel decreases it. The reversal trips up nearly everyone at first, so it is worth stating the rule plainly and keeping it handy. Entering these three values into the calculator and toggling between parallel and series returns both totals, so you can see the contrast directly.
The reason to combine capacitors at all comes down to what a design needs, and parallel is by far the more common choice. The dominant application is power-supply smoothing. Electronic devices need a stable voltage, but the raw output of a power supply ripples. Placing capacitors in parallel across the supply increases the total capacitance, and that larger reservoir of stored charge absorbs the ripples — filling in the dips and shaving the peaks to deliver steadier power. When you see banks of capacitors on a circuit board near the power input, they are almost always in parallel for exactly this bulk-storage reason. Adding capacitance is as simple as adding another capacitor to the group.
Series combinations are less common but solve a specific problem: voltage rating. Every capacitor has a maximum voltage it can withstand before its insulating layer breaks down. When a circuit's voltage exceeds what any single available capacitor can handle, wiring capacitors in series divides the total voltage across them, so each sees only a portion. The trade-off is that the total capacitance drops below that of the smallest unit — you gain voltage tolerance at the cost of capacitance. Series is therefore a deliberate engineering choice for high-voltage situations, not a default.
The cleanest way to never get confused is to anchor on the underlying physics. Capacitors in parallel share more plate area and therefore store more charge, so their values add — like resistors in series. Capacitors in series effectively increase the separation between plates and reduce the combined ability to store charge, so they combine by reciprocals — like resistors in parallel. Holding onto that one symmetry, rather than memorizing four disconnected rules, keeps the whole picture straight. The companion parallel resistor calculator handles the resistor side of the mirror, and once a circuit is simplified, Ohm's law ties the pieces together. One unit reminder closes the loop: keep every capacitance in the same unit before combining, since mixing microfarads and nanofarads without converting produces a meaningless total.
Remember the mirror: capacitors in parallel add, capacitors in series use reciprocals — the exact opposite of resistors.
To increase capacitance, wire capacitors in parallel and simply sum the values — the standard approach for power-supply smoothing.
A series total is always smaller than your smallest capacitor. If your series answer is larger, you’ve likely selected the wrong mode.
Keep all values in the same unit — mixing microfarads and nanofarads without converting will give a meaningless total.