# Capacitors in Series & Parallel Calculator

Calculate total capacitance for capacitors in series or parallel. Find stored charge and energy. Supports 2-3 capacitors.

## What this calculates

Capacitors can be combined in series or parallel to achieve a desired total capacitance. In parallel, capacitances add directly. In series, the reciprocals add. This calculator computes the total capacitance, stored charge, and stored energy for up to three capacitors in either configuration.

## Inputs

- **Capacitor C1** (μF) — min 0 — Capacitance of the first capacitor in microfarads.
- **Capacitor C2** (μF) — min 0 — Capacitance of the second capacitor in microfarads.
- **Capacitor C3 (optional)** (μF) — min 0 — Optional third capacitor. Leave at 0 to use only two capacitors.
- **Configuration** — options: Parallel, Series — How the capacitors are connected.
- **Applied Voltage** (V) — min 0 — Voltage across the capacitor combination (for charge and energy calculations).

## Outputs

- **Total Capacitance** (μF) — Combined capacitance of the configuration.
- **Charge Stored** (μC) — Total charge stored at the applied voltage (Q = CV).
- **Energy Stored** (μJ) — Energy stored in the capacitor combination (E = ½CV²).

## Details

When capacitors are connected in parallel, each capacitor has the same voltage across it, and the total capacitance is simply the sum: Ctotal = C1 + C2 + C3. Parallel capacitors are used to increase capacitance and reduce equivalent series resistance (ESR).

When capacitors are connected in series, each stores the same charge, and the total capacitance is always less than the smallest individual capacitor: 1/Ctotal = 1/C1 + 1/C2 + 1/C3. Series capacitors are used to increase the voltage rating; the total voltage is shared across all capacitors.

The stored charge is Q = CV and the stored energy is E = ½CV². These quantities are important in power supply design, energy storage applications, and timing circuits. For example, a 1000 μF capacitor charged to 5V stores 12.5 mJ of energy.

## Frequently Asked Questions

**Q: Why is series capacitance always less than the smallest capacitor?**

A: In series, each capacitor stores the same charge. The voltage is divided among them, so the combination needs less charge per volt of applied voltage. That is, it has less capacitance.

**Q: When would I use capacitors in series?**

A: Series connection increases the voltage rating. If you need to handle 200V but only have 100V-rated capacitors, two in series can share the voltage. Note that the total capacitance is halved.

**Q: Can I mix different capacitance values?**

A: Yes. The formulas work for any combination of values. In parallel, the total is simply the sum. In series, smaller capacitors dominate the result since they contribute most to the reciprocal sum.

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Source: https://vastcalc.com/calculators/technology/capacitors-series-parallel
Category: Technology
Last updated: 2026-04-21