ELECTRONICS · CALCULATOR

Sum of capacitors calculator

Free sum of capacitors calculator: get parallel and series from capacitance 1 and capacitance 2. The formula is shown; verify against the NEC.

Written by Chameera Sampath · Not yet reviewed by a licensed electrician. See the methodology.

US (NEC) only · NFPA 70 / NEC — locally adopted editionDefaults are US values. Verify the locally adopted NEC edition and project data.Official reference ↗

Project inputs

Measurements

Capacitance 1

µF

Capacitance 2

µF

Updates as inputs change. Unit changes preserve the same physical values.

THE MATH BEHIND THE ANSWER

Method & assumptions

Cparallel = C1 + C2; Cseries = C1C2 / (C1 + C2)

Series capacitor voltage sharing is not assessed.

Results do not check every aspect of an electrical installation. The calculators follow US (NEC) practice only; a regional preset changes defaults such as voltage and units, and no result certifies NEC compliance.

Sources and validation →

Worked example

Capacitance 1: 100 µF · Capacitance 2: 200 µF

Parallel: 300 µF · Series: 66.667 µF

This example uses the stated inputs; results for the entered values appear above.

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