What Is Capacitance?

A capacitance calculator computes how much charge a capacitor stores using the parallel-plate formula C = kε₀A/d. Capacitance rises with larger plate area and falls with wider plate separation; the dielectric material multiplies the result by its relative permittivity k.

The Parallel-Plate Formula

C = kε₀A/d. The vacuum permittivity ε₀ is 8.854 × 10⁻¹² F/m. With A in square meters and d in meters, the result is in farads. In practice capacitances are tiny — this calculator displays picofarads, nanofarads, and microfarads as appropriate.

Where Capacitors Are Used

Capacitors smooth voltage ripple in power supplies, store flash energy in cameras, couple and filter audio signals, and tune radio circuits. The stored charge Q = CV and energy ½CV² let engineers size components for the exact requirements of a circuit.