The figure Bellow shows how capacitors can be wired in series. The equivalent capacitance is calculated by the next formulas.
Formula 1
1/C = 1/C1 + 1/C2 + 1/C3 + … + 1/Cn
Where:
C is the equivalent capacitance in farads (F) or any submultiples
C1, C2, C3... Cn are parallel associated capacitors in farads (F) or any submultiples
Derivated Formulas:
Formula 2
For all the capacitors having the same value: (C1 = C2 = C3 =... Cn):
C = C1 / n
Formula 3
For two capacitors (C1 e C2):
C = (C1 x C2) / (C1 + C2)
Application Example:
What is the equivalent capacitance of a 20 nF wired in series with a 30 nF capacitor?
Data:
C1 = 20 nF
C2 = 30 nF
C = ?
Using formula 3
C = (C1 X C2)/(C1 + C2)
C = (20 x 30)/(20 + 30)
C = 600/50
C = 12 nF
