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How to use
This tool calculates equivalent capacitance for ideal capacitors in series or parallel. Parallel capacitances add directly; series capacitances combine through reciprocal sums. Enter values using one common unit: F, mF, µF, nF or pF.
- Choose series or parallel.
- Enter capacitor values separated by commas or spaces.
- Choose their common unit and calculate equivalent capacitance.
How it is calculated
Example
Example: 10µF and 22µF in parallel give 32µF. In series, Ceq=1/(1/10+1/22)≈6.875µF.
Important notes
The calculation assumes ideal capacitors at nominal values. It does not model ESR, leakage, tolerance, voltage coefficient or safe voltage sharing in series. Use component datasheets for real circuits.
Worked examples and interpreting results
Capacitors 10 and 20 µF give 30 µF in parallel and about 6.6667 µF in series. Series capacitance is smaller than the smallest capacitor.
| Case | Calculation | Result |
|---|---|---|
| In parallel | 10 + 20 | 30 µF |
| In series | 1 ÷ (1/10 + 1/20) | 6.666667 µF |
How to check the result
Select µF, enter 10 and 20, then compare connections. These are ideal capacitances; voltage ratings, component tolerances and parasitics are not determined from capacitance alone.
Frequently asked questions
Why does capacitance decrease in series?
Because reciprocal capacitances add, making the equivalent smaller than the smallest individual capacitor.
What happens in parallel?
Capacitances add directly, so the equivalent exceeds any single capacitor.
Can I mix µF and nF in one list?
This version uses one common unit for the list; convert values to a common unit first.
Does it calculate voltage rating?
No. It calculates ideal equivalent capacitance only and does not predict real series voltage sharing.