Capacitor Series Connection
Calculator and formula for a capacitor series connection with two capacitors
Capacitance Calculator
Two Capacitors in Series
This function calculates the total capacitance or one of the capacitors in a series connection of two capacitors. Select what to calculate and enter the known values.
Circuit Diagram & Formulas

Calculate Total Capacitance
Formula for the total capacitance of two capacitors connected in series.
Calculate Capacitor C₂
To calculate C₂ given the total capacitance and C₁.
More Capacitors?
For series connections with more than 2 capacitors, use the general function.
Theory - Two Capacitors in Series
Basics of Two-Capacitor Series Connection
In a series connection of two capacitors, the calculation of the total capacitance is particularly simple because a direct formula can be used. This circuit is often used in practice.
Calculation Formulas
Total Capacitance
The total capacitance is the product of the two capacitances divided by their sum.
Capacitor C₂
Calculation of C₂ when C₁ and the total capacitance are known.
Calculation Examples
Example 1: Total Capacitance
Given: C₁ = 100μF, C₂ = 220μF
Result: The total capacitance is 68.75μF.
Example 2: Capacitor C₂
Given: C₁ = 100μF, Ctotal = 60μF
Result: Capacitor C₂ has 150μF.
Practical Applications
Capacitance Adjustment:
Voltage Divider:
Filter Design:
Important Notes
- The total capacitance is always smaller than the smallest individual capacitance
- For equal capacitance values: Ctotal = C/2
- Voltages are distributed inversely proportional to the capacitances
- To calculate C₂, Ctotal must be less than C₁
- All capacitors carry the same charging current
- The total voltage rating is the sum of the individual voltages
Special Case: Equal Capacitances
Two Identical Capacitors
For two identical capacitors with capacitance C, the total capacitance is exactly half.