What is the Series & Parallel Capacitor Calculator?
This calculator combines 2–20 positive capacitance values into one nominal equivalent for an all-series or all-parallel group. Every capacitor may have a different value. It compares both arrangements and highlights the one selected, so you can see why the same components give different totals when their connection changes.
Capacitors follow different combination rules from resistors. For a resistor group, use the separate Series & Parallel Resistor Calculator. This page models capacitance rather than resistance, and optional voltage adds capacitor charge and stored energy rather than a steady DC resistor current.
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Optional capacitance meters (paid link) can help check an isolated, discharged component. Measurement results depend on the instrument and conditions; no purchase is required.
How to enter capacitors in series or parallel
- Choose an all-series or all-parallel connection.
- Enter 2–20 positive capacitor values, separated by commas, semicolons or new lines.
- Choose the default pF, nF, µF, mF or F unit for numbers without a suffix.
- For mixed units, enter explicit suffixes such as 100nF, 0.1uF, 10µF or 1mF.
- Optionally enter DC voltage across the complete group, then calculate.
Explicit suffixes override the default unit. Changing the default unit reinterprets unsuffixed numbers; it does not rewrite the list. Use decimal points and avoid thousands commas, because commas separate components. Zero, negative values, missing entries and unsupported suffixes are rejected.
One farad equals 1,000 mF, 1 million µF, 1 billion nF or 1 trillion pF. Optional capacitor assortments (paid link) must be checked for their actual capacitance, polarity, tolerance and voltage ratings. A mathematical equivalent does not establish that a physical combination is suitable.
Series and parallel capacitance formulas
Series: 1/Ceq = 1/C1 + 1/C2 + … + 1/Cn
Two in series: Ceq = C1 × C2 / (C1 + C2)
Equivalent charge: Q = Ceq × V
Stored energy: E = ½ × Ceq × V²
Convert all values into the same unit before combining them. Parallel capacitance is the sum; positive series capacitance is below the smallest component. If n capacitors all have value C, their parallel equivalent is nC and their series equivalent is C/n.
With the optional voltage, the model assumes initially uncharged ideal capacitors and no trapped charge on isolated junctions. In series, each stores the same charge magnitude and its voltage is Q/Ci. In parallel, each has the entered voltage and its charge is CiV. The source-terminal charge CeqV is not the sum of the equal individual series charges.
Capacitor calculator examples: two and three capacitors
Two equal 10 µF capacitors give 20 µF in parallel or 5 µF in series. For three equal 10 µF capacitors, the totals are 30 µF in parallel and about 3.333333 µF in series. These are alternative connections, not a mixed circuit.
For 10 µF and 20 µF in series at 12 V, Ceq = 200/30 ≈ 6.666667 µF. Equivalent charge is 80 µC, so the individual voltages are 8 V and 4 V. Total stored energy is 0.00048 J. The smaller capacitor has the larger voltage in this ideal model.
Put those same values in parallel at 12 V: Ceq = 30 µF, source-terminal charge = 360 µC and total energy = 0.00216 J. Each capacitor has 12 V across it. For charging time through a resistor rather than a final network total, use the RC Time Constant Calculator.
Understand voltage sharing, charge and stored energy
The optional voltage is applied across the complete selected group. Series voltage division follows inverse capacitance only under the stated ideal initial-charge assumptions. Leakage, balancing resistors, pre-existing charge and unequal operating conditions can change real voltage sharing. This tool does not add component voltage ratings or approve a capacitor bank.
Energy and charge are shown in joules and coulombs. A displayed small nominal capacitance can still store meaningful energy at a sufficiently high voltage, and disconnecting a supply does not prove that a capacitor is discharged. This tool does not choose a discharge procedure or resistor rating.
Optional resistor assortments (paid link) can help compare nominal values for a separate RC model. Use the Ohm’s Law Calculator for a resistive relationship, and check component data separately.
Accuracy and limitations of the capacitor network model
This tool handles one all-series or all-parallel group, not an arbitrary mixed schematic, motor-start sizing, power-factor correction, crossover design or capacitor code identification. For a mixed network, only reduce groups when the actual circuit topology permits it. The model excludes ESR, leakage, tolerance, temperature dependence, dielectric absorption and frequency behavior.
Each input must represent 1e−15 through 1,000 F. Optional applied voltage is 0–60 V. These are computational limits, not component or application approvals. Results display up to seven significant digits; arithmetic retains normal floating-point precision. Series combination uses scaled reciprocals and parallel combination uses compensated summation.
Optional solderless breadboards (paid link) are for compatible low-voltage prototypes within their ratings. Do not infer polarity or acceptable voltage/current from a capacitance total. For an output ratio made from two resistors, use the existing Voltage Divider Calculator.
Series & Parallel Capacitor Calculator FAQs
Add the reciprocals of their capacitances, then take the reciprocal of that sum. For positive values, the series equivalent is below the smallest capacitor.
Add all capacitances in the same unit. For example, 10 µF and 20 µF in parallel give 30 µF.
Yes. Choose a default unit for unsuffixed values or enter explicit pF, nF, uF, µF, mF or F suffixes. Explicit suffixes take precedence.
Yes, when optional DC voltage is supplied. It assumes ideal initially uncharged capacitors with no trapped junction charge; real leakage and balancing can change series sharing.
This tool does not calculate a combined voltage rating. Actual ratings, leakage, polarity, balancing and operating conditions must be checked separately.
It handles one all-series or all-parallel group. Reduce mixed networks only where topology permits; it does not analyze an arbitrary schematic.
Sources and methodology
Independent circuit equations and implementation, reviewed October 25, 2026. Manufacturer datasheets control real component ratings. The linked organizations do not endorse this tool.