Parallel Capacitance

Formula

Description

Capacitors in parallel add directly, which is the opposite of how resistors combine in parallel. This is because connecting capacitors in parallel effectively increases the total plate area while maintaining the same distance between plates. Parallel capacitors share the same voltage and each contributes independently to the total stored charge. This is the most common way to increase total capacitance in power supply filtering, where multiple capacitors of different types are placed in parallel to cover a wide frequency range.

Variables

• Ctotal — Total equivalent capacitance (F)
• C1, C2, ... Cn — Individual capacitor values (F)

Practical Notes

In power supply design, combining a large electrolytic (for bulk energy storage) with a small ceramic capacitor (for high-frequency bypassing) in parallel gives excellent filtering across the full frequency spectrum. Each type compensates for the other's weaknesses.