How to Calculate Capacitance

What is Capacitance?

A capacitor stores electrical energy in an electric field between two conductive plates separated by an insulating dielectric. Capacitance C (farads) measures how much charge Q is stored per unit voltage V: C = Q/V. Capacitors are used in power supplies for smoothing, in filters, timing circuits, and energy storage (supercapacitors).

Formula

Q = CV (charge = capacitance × voltage)

Q: CV (charge = capacitance × voltage) — CV (charge = capacitance × voltage)
CV: capacitance × voltage) — capacitance × voltage)

Step-by-Step Guide

1Q = CV (charge = capacitance × voltage)
2Energy stored: E = ½CV² (joules)
3Capacitors in parallel: C_total = C₁ + C₂ + ...
4Capacitors in series: 1/C_total = 1/C₁ + 1/C₂ + ...
5RC time constant: τ = RC — time to charge to 63.2% of supply voltage

Worked Examples

Input

100 μF capacitor, 12 V

Result

Q = 100×10⁻⁶ × 12 = 1.2 mC; E = ½ × 100×10⁻⁶ × 144 = 7.2 mJ

Input

1 F supercapacitor, 2.7 V

Result

E = ½ × 1 × 7.29 = 3.645 J — can flash an LED for minutes

Frequently Asked Questions

What is Capacitor Stores Electrical Energy In An Electric Field Between Two Conductive Plates Separated By An Insulating Dielectric?

How accurate is the Capacitor Stores Electrical Energy In An Electric Field Between Two Conductive Plates Separated By An Insulating Dielectric calculator?

The calculator uses the standard published formula for capacitor stores electrical energy in an electric field between two conductive plates separated by an insulating dielectric. Results are accurate to the precision of the inputs you provide. For financial, medical, or legal decisions, always verify with a qualified professional.

What units does the Capacitor Stores Electrical Energy In An Electric Field Between Two Conductive Plates Separated By An Insulating Dielectric calculator use?

This calculator works with inches, percentages. You can enter values in the units shown — the calculator handles all conversions internally.

What formula does the Capacitor Stores Electrical Energy In An Electric Field Between Two Conductive Plates Separated By An Insulating Dielectric calculator use?

The core formula is: Q = CV (charge = capacitance × voltage). Each step in the calculation is shown so you can verify the result manually.

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