Electrical · Passive networks
Capacitor Network Calculator
Combine series strings and parallel branches — the schematic redraws as you type and C_eq lands with a satisfying pop.
Parallel branches
Each branch is a series string; branches combine in parallel
Result
Equivalent capacitance
1/C_eq = Σ(1/C_branch), C_branch = 1/Σ(1/C_series)
Build your network branch by branch — series caps inside each path, parallel paths as separate branches.
Series, parallel, and branch reduction — the models this calculator uses for C_eq.
This tool uses a branch model: capacitors within a branch are in series; branches themselves are in parallel. That covers pure series, pure parallel, and mixed topologies without drawing a full node matrix.
| Topology | Example | C_eq | Note |
|---|---|---|---|
| Two in series | 100 µF + 100 µF | 50 µF | Half value, doubles voltage rating |
| Two in parallel | 100 µF ∥ 100 µF | 200 µF | Values add directly |
| Three in series | 10 µF × 3 | 3.33 µF | 1/C = 1/10 + 1/10 + 1/10 µF⁻¹ |
| Mixed branch | (10∥10) series 5 | 7.5 µF | Reduce each branch first, then combine |
- Unlike resistors, series capacitors decrease total C — the reciprocal law mirrors parallel resistors.
- Parallel caps share the same voltage; series strings divide voltage by the cap ratio.
- Electrolytics in series need balancing resistors — their leakage currents are never matched.
- Decoupling banks on PCBs are effectively parallel branches at high frequency.
- Tolerance stack-up in series strings can leave one cap seeing most of the voltage.
- Film and ceramic caps in parallel at the same node add their values for bulk + HF response.
Not every schematic maps cleanly to “series strings in parallel branches.” Delta–wye transforms, caps tied to intermediate nodes, or bridge networks need nodal analysis instead. For standard power-supply banks, filter ladders, and coupling stacks, the branch model matches how engineers sketch the problem on paper.