Series and parallel capacitor calculator
Capacitors follow the opposite rule to resistors: they add directly in parallel and by reciprocals in series. Type the values, pick the unit and connection.
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How to use it
- Enter connection, unit and capacitor values.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
Parallel: C = C1 + C2 + C3. Series: 1 ÷ C = 1 ÷ C1 + 1 ÷ C2 + 1 ÷ C3. The result is in the same unit you entered.
Example
Inputs: Connection = Parallel, Unit = microfarad (µF). Result: Equivalent capacitance: 79 µF; Short form: 79 µF; Number of capacitors: 3.
Limits and caveats
- Type every value in the unit you selected.
- Capacitors in series share voltage in inverse proportion to capacitance; make sure each one stays within its voltage rating.
Questions about this tool
Why does capacitance drop in series?
Series connection acts like a wider gap between the plates, so total capacitance falls below the smallest capacitor.
What do two 10 µF capacitors in series give?
5 µF, half of one of them. In parallel they give 20 µF.
When would I put capacitors in series?
When you need a higher voltage rating than one capacitor offers and can accept lower capacitance.