Electronics Calculator

Parallel Capacitor Calculator

Calculate the equivalent capacitance of capacitors connected in parallel. Enter up to 10 capacitors and the applied voltage to calculate total capacitance, charge, stored energy and the electrical contribution of each capacitor.

Capacitors in Parallel

Add two or more capacitors. The equivalent capacitance is the sum of all capacitor values.

Quick presets
V
The same voltage appears across every capacitor in an ideal parallel circuit. Do not exceed the voltage rating of any individual capacitor.

Results

Equivalent capacitance and electrical values are calculated automatically.

Equivalent Capacitance
—
Ctotal = ΣCi
Total Charge
—
Q = Ctotal × V
Total Energy
—
E = ½CtotalV²
Applied Voltage
—
Capacitors
—
Total Charge
—

Individual Capacitor Values

Capacitor Capacitance Voltage Charge Energy Share

Parallel Capacitor Formula

When capacitors are connected in parallel, their capacitances add directly. Each capacitor is connected across the same two circuit nodes, so every capacitor experiences the same voltage.

Ctotal = C1 + C2 + C3 + ... + Cn
Total capacitance of capacitors connected in parallel

Charge

Q = C × V
Charge stored by an individual capacitor

Stored Energy

E = ½CV²
Energy stored in a capacitor

How Parallel Capacitors Work

A parallel capacitor network connects the positive terminal of every capacitor to one circuit node and the negative terminal of every capacitor to the other node.

Because all capacitors are connected across the same two nodes, the voltage across each capacitor is identical.

Example: two 100 nF capacitors

Ctotal = 100 nF + 100 nF
Ctotal = 200 nF

With a 12 V supply:
Q = 200 nF × 12 V
Q = 2.4 µC

Same Voltage, Different Charge

The voltage across every capacitor is the same, but the charge does not have to be the same. A larger capacitor stores proportionally more charge at the same voltage.

For example, with 12 V applied, a 100 nF capacitor stores 1.2 µC while a 1 µF capacitor stores 12 µC. Both capacitors have the same 12 V across them.

Parallel Capacitor Circuit

In a parallel connection, all capacitors share the same two electrical nodes.

C₁ C₂ C₃ + − Same voltage across every capacitor

Applications of Parallel Capacitors

  • Power-supply filtering and smoothing.
  • Local bypass and decoupling near integrated circuits and digital devices.
  • Increasing the total capacitance available from standard component values.
  • Energy storage and DC-link capacitor banks.
  • Combining different capacitor technologies to cover different frequency ranges.
  • Audio, RF and analog circuit filtering.
  • Creating a desired capacitance when one standard component value is unavailable.

Practical Design Considerations

Voltage Rating

Parallel connection does not increase the voltage rating of the capacitor bank. Every capacitor sees the full circuit voltage, so each component must be appropriately rated.

Tolerance

Real capacitors have tolerance. The actual total capacitance can therefore differ from the nominal sum of the marked values.

ESR and ESL

Real capacitors also have equivalent series resistance (ESR) and equivalent series inductance (ESL). These characteristics can matter significantly in high-current or high-frequency applications.

Different Capacitor Types

Designers sometimes combine ceramic, film, electrolytic or other capacitor types in parallel. Their different electrical characteristics can make the combination useful across a wider frequency range.

Parallel Capacitor Examples

Example 1: Equal Capacitors

C₁ = 100 nF
C₂ = 100 nF

Ctotal = 100 + 100
Ctotal = 200 nF

Example 2: Three Capacitors

C₁ = 100 nF
C₂ = 220 nF
C₃ = 330 nF

Ctotal = 100 + 220 + 330
Ctotal = 650 nF

Example 3: Charge

Ctotal = 1 µF
V = 12 V

Q = CV
Q = 1 µF × 12 V
Q = 12 µC

Related Electronics Calculators

Explore more free electronics calculators on OCTOPART.ORG.

Series Capacitor Calculator

Calculate equivalent capacitance for capacitors connected in series.

Capacitor Energy Calculator

Calculate energy stored in a capacitor from capacitance and voltage.

Capacitor Reactance Calculator

Calculate capacitive reactance from frequency and capacitance.

Capacitor Code Calculator

Decode common capacitor markings and three-digit capacitor codes.

Series Resistor Calculator

Calculate total resistance for resistors connected in series.

Parallel Resistor Calculator

Calculate equivalent resistance for resistors connected in parallel.

Ohm’s Law Calculator

Calculate voltage, current, resistance and power using Ohm’s law.

Electrical Unit Converter

Convert common electrical and electronic engineering units.

Parallel Capacitor Calculator FAQ

Common questions about calculating capacitance in parallel capacitor circuits.

For capacitors connected in parallel, add their capacitances: Ctotal = C1 + C2 + C3 + ... + Cn.
Yes. For positive capacitance values, the total capacitance in a parallel network is the sum of all capacitors, so it is greater than any individual capacitor.
Every capacitor connected in parallel has the same voltage across it as the applied circuit voltage.
No. The voltage is the same, but the charge on each capacitor depends on its capacitance. For each capacitor, Q = C × V.
Parallel capacitors can be used to increase total capacitance, provide local energy storage, reduce supply impedance over relevant frequency ranges, or combine available capacitor values to reach a desired capacitance.
Two equal capacitors have a total capacitance that is twice the value of either capacitor. For example, two 100 nF capacitors produce 200 nF total capacitance.
The energy stored in an individual capacitor is E = 1/2 × C × V². The total energy is the sum of the individual energies, which is also Etotal = 1/2 × Ctotal × V².
No. The voltage rating of a parallel capacitor bank is generally limited by the lowest voltage-rated capacitor in the network. Do not exceed the rating of any individual capacitor.