🔋 Series & Parallel Capacitor Calculator
Add any number of capacitors and get the total capacitance, parallel add, series combine as reciprocals (the reverse of resistors).
Capacitances (µF)
Total capacitance (series)
56.8966 µF
1/Ctotal = 1/C1 + 1/C2 + …
Capacitors are the opposite of resistors: parallel add; series combine as 1/C_total = Σ(1/Cᵢ). 🔒 Computed in your browser.
How the series & parallel capacitor calculator works
Capacitors combine oppositely to resistors: in parallel they add, C_total = C₁ + C₂ + …; in series the reciprocals add, 1/C_total = 1/C₁ + 1/C₂ + …. Add a row per capacitor, choose the arrangement, and the tool computes the equivalent capacitance.
Easy to mix up: parallel capacitors add (like series resistors), series capacitors combine as reciprocals (like parallel resistors). The stored charge is Q = CV and energy ½CV².
Frequently asked questions
How do capacitors combine in parallel?
They add: C_total = C₁ + C₂ + …. Parallel plates effectively increase the total plate area, so capacitance grows.
How do capacitors combine in series?
As reciprocals: 1/C_total = 1/C₁ + 1/C₂ + …, so the total is smaller than the smallest capacitor, the opposite of resistors.
Why are capacitor rules the reverse of resistors?
Because capacitance relates to charge stored per volt, not opposition to current. Series stacking increases the effective plate separation, reducing capacitance.
What is the charge and energy on a capacitor?
Charge Q = CV, and stored energy E = ½CV² = ½Q²/C, where V is the voltage across it.
What units should I use?
Keep every capacitor in the same unit (e.g. all microfarads); the total is in that unit.
Worked example: three capacitors
Three 10 µF capacitors in parallel add to 30 µF. The same three in series give 1/C = 3 × (1/10) = 0.3, so C = 3.33 µF, smaller than any single one.
Does combining capacitors change the voltage rating?
Yes. In series the applied voltage divides across the capacitors, so the string withstands more voltage; in parallel every capacitor sees the full voltage, so the group is limited by the lowest-rated one. This tool computes capacitance, not voltage ratings, check those separately.
What is a farad?
The SI unit of capacitance: one farad (F) stores one coulomb of charge per volt applied. A farad is very large, so real capacitors are usually rated in microfarads (µF), nanofarads (nF) or picofarads (pF).
Worked example: two capacitors in series
For 4 µF and 12 µF in series, 1/C = 1/4 + 1/12 = 4/12 = 1/3, so C = 3 µF, smaller than either one, as series capacitance always is.