Capacitor Series & Parallel Calculator
Combine any number of capacitors in series or parallel — parallel adds, series uses the reciprocal sum — with SI-prefix input.
Combining capacitors
Capacitors combine the opposite way to resistors.In parallel the plate areas effectively add, so the capacitances add. In series the reciprocals add, giving a total smaller than the smallest capacitor.
Parallel: C = C₁ + C₂ + … + Cₙ
Series: 1/C = 1/C₁ + 1/C₂ + … + 1/Cₙ
For two capacitors in series this is the "product over sum" rule: C = C₁·C₂ / (C₁ + C₂). Two equal capacitors in series give half the value.
Why it matters
Parallel capacitors are common for bulk plus high-frequency decoupling; series capacitors split voltage and are used to reach non-standard values or higher working voltages. Working with a resistor and capacitor together? See the RC time constant calculator.