Total Series Capacitance
Enter at least two capacitor values below.
Capacitor Values
What Is a Series Capacitor Calculator?
A Series Capacitor Calculator determines the equivalent capacitance of two or more capacitors connected in series. Capacitors in series behave differently from resistors because adding more capacitors reduces the overall capacitance of the circuit.
This calculator lets you enter capacitor values using picofarads, nanofarads, microfarads, millifarads or farads. All values are automatically converted before the equivalent capacitance is calculated.
How to Use the Series Capacitor Calculator
- Enter the capacitance value of the first capacitor.
- Select its unit such as pF, nF, µF, mF or F.
- Enter the value and unit for the second capacitor.
- Click Add Capacitor if you need additional capacitors.
- Click Calculate Capacitance.
- The equivalent series capacitance will appear instantly.
Series Capacitor Formula
For capacitors connected in series, the reciprocal of the equivalent capacitance is equal to the sum of the reciprocals of each individual capacitor.
After adding the reciprocal values, take the reciprocal of the result to find the total capacitance.
Two Capacitor Formula
When only two capacitors are connected in series, you can use a simpler product-over-sum formula.
Series Capacitor Example
Suppose two capacitors of 10 µF and 20 µF are connected in series. Using the two-capacitor formula:
CT = 200 / 30
CT ≈ 6.67 µF
Notice that the equivalent capacitance is lower than the value of the smallest capacitor. This is always true for positive capacitors connected in series.
Why Capacitors Are Connected in Series
Higher Voltage Rating
Series capacitor arrangements can distribute voltage across multiple components when designed correctly.
Specific Capacitance
Series combinations can be used when a particular lower capacitance value is required.
Learning Circuits
Series capacitance calculations are commonly used in electronics education and circuit analysis.
Capacitance Units
The standard SI unit of capacitance is the farad (F). Because one farad is relatively large for many electronic applications, smaller units are commonly used.
| Unit | Symbol | Equivalent in Farads |
|---|---|---|
| Farad | F | 1 F |
| Millifarad | mF | 0.001 F |
| Microfarad | µF | 0.000001 F |
| Nanofarad | nF | 0.000000001 F |
| Picofarad | pF | 0.000000000001 F |
Series vs Parallel Capacitors
Series Capacitors
The reciprocal capacitances are added. The equivalent capacitance becomes lower than the smallest individual capacitor.
Parallel Capacitors
Capacitance values are added directly, so the total capacitance increases as more capacitors are connected.
Quick Calculation
Using the correct formula prevents common unit conversion and manual calculation errors.
Frequently Asked Questions
How do you calculate capacitors in series?
Add the reciprocal of each capacitor value and then take the reciprocal of the result. This gives the equivalent capacitance.
Does capacitance increase or decrease in series?
Capacitance decreases when capacitors are connected in series. The total capacitance is always less than the smallest individual capacitor for positive capacitance values.
Can I use different capacitance units?
Yes. This calculator supports pF, nF, µF, mF and F. Each capacitor can use a different unit because values are converted automatically.
What is the formula for two capacitors in series?
For two capacitors, use CT = (C1 × C2) / (C1 + C2). This is equivalent to the reciprocal formula.
Can I calculate more than two capacitors?
Yes. Click the Add Capacitor button to add as many capacitor input fields as required for your calculation.
What happens with equal capacitors in series?
If identical capacitors are connected in series, the total capacitance equals the capacitance of one capacitor divided by the number of capacitors.