Parallel & Series Capacitor Calculator
Compute the parallel and series equivalent capacitance of several capacitors at once (in µF).
Note: capacitors add in parallel and combine reciprocally in series — the opposite of resistors.
Disclaimer: This calculator is provided for general informational and educational purposes only, on an “as is” basis and without any warranty of accuracy or fitness for a particular purpose. Results may contain errors — always verify independently before relying on them in real designs. PartAndStock accepts no liability for any loss or damage arising from use of this tool, including when embedded on third-party sites.
How to use
- 1Enter the capacitor values in µF, separated by commas or spaces.
- 2The parallel (sum) and series equivalents are computed at the same time.
- 3Very small results auto-format to nF/pF, very large ones to F.
How it works
Enter capacitor values in µF and get both the parallel (sum) and series equivalent capacitance instantly. It works the opposite way to resistors.
Why it's the opposite of resistors
Capacitors follow the inverse rule of resistors. In parallel it's as if the plate areas add, so capacitance sums (Cₜ = ΣCᵢ). In series the effective plate spacing grows, so capacitance drops and conductance-like terms (1/C) add — the equivalent ends up smaller than even the smallest capacitor.
Voltage and practical use
Parallel connection raises total capacitance and filters a supply rail; its voltage rating is limited by the lowest-rated part. Series connection raises voltage rating (voltage splits across the parts) but lowers capacitance; balancing resistors may be needed so the voltage divides evenly.
Worked examples
- Parallel: 100 µF + 220 µF + 470 µF = 790 µF
- Series: 100 µF and 100 µF → 50 µF (two equal → half)
- Series: 10 µF and 22 µF → 6.875 µF
Quick Rules (opposite of resistors)
| Connection | Formula | Result direction |
|---|---|---|
| Parallel | Cₜ = ΣCᵢ | Above the largest |
| Series (2) | C1·C2/(C1+C2) | Below the smallest |
| Series (n equal) | C / n | One nth of C |