⚡ Capacitance: Calculator

Calculate parallel plate capacitance or combine multiple capacitors in series and parallel.

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What Is Capacitance?

Capacitance measures a component's ability to store electrical charge, expressed in Farads (F). Since a Farad is a huge unit, most real-world capacitors are rated in microfarads (µF), nanofarads (nF), or picofarads (pF).

Parallel Plate Capacitor Formula

C = ε₀ × κ × A ÷ d
ε₀ = 8.854 × 10⁻¹² F/m (permittivity of free space)
κ = dielectric constant of the insulating material
A = plate area (m²) · d = distance between plates (m)

A parallel plate capacitor's capacitance increases with larger plate area and higher-permittivity dielectric material, and decreases as the plates are moved farther apart.

Capacitors in Series and Parallel

Parallel: C_total = C₁ + C₂ + ... + Cₙ
Series: 1 ⁄ C_total = 1⁄C₁ + 1⁄C₂ + ... + 1⁄Cₙ

Notice this is the opposite pattern from resistors: capacitors in parallel simply add up, while capacitors in series combine like resistors in parallel — the total is always smaller than the smallest individual capacitor.

Common Dielectric Constants

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❓ Frequently Asked Questions

Why do capacitors in series add differently than parallel?
In series, the same charge must pass through each capacitor while voltage divides between them, which mathematically works out to reciprocal addition — the same relationship resistors follow when wired in parallel.
What is a dielectric constant?
The dielectric constant (κ) describes how much a material increases a capacitor's charge storage compared to a vacuum. Materials with higher κ values, like ceramics, allow much smaller physical capacitors to store the same charge.
What units should I use for the parallel plate formula?
This calculator accepts plate area in square centimeters and distance in millimeters for convenience, converting internally to the meters and square meters used in the underlying physics formula.
Why is my calculated capacitance shown in different units (pF, nF, µF)?
The calculator automatically selects the most readable unit (Farads, milli-, micro-, nano-, or picofarads) based on the magnitude of the result, since real capacitors span an enormous range of sizes.
Does this calculator account for capacitor tolerance or voltage rating?
No — it calculates ideal theoretical capacitance only. Real components have manufacturing tolerances (often ±5-20%) and maximum voltage ratings that must also be considered in circuit design.

🏆 About This Tool — Accuracy & Trust

🔒 Data Privacy: All calculations run entirely within your browser using JavaScript. Nothing you enter here is ever transmitted to our servers, stored, sold, or shared.

📐 Accuracy Note: This tool uses standard, widely published formulas and guidelines. Results are estimates for informational purposes; for financial, medical, or engineering decisions, consult a licensed professional.

📅 Last Updated: September 2026.