# Formula Cylindrical Capacitor Capacitance    Length    Inner radius    Outer radius    Relative permittivity    Permittivity of free space ## Capacitance

Unit
Capacitance is a measure of how much charge can be separated on the electrodes of the cylindrical capacitor, in other words - how good the cylinder can store electric charge.

## Length

Unit
Length of the cylinder. The longer the cylinder, the greater its electric capacitance.

Unit
Radius of the inner electrode of the charged cylindrical capacitor.

Relative permittivity depends on the dielectric medium between the outer and inner cylinder and indicates the permeability of the electric field. In vacuum it has the value: $$\varepsilon_r ~=~ 1$$. By using a different medium (e.g. air or water) between the electrodes of the cylinder capacitor, the capacitance of the cylinder can be increased.
Permittivity of free space is a physical constant and has the value: $$\varepsilon_0 = 8.854187817 ~\cdot~ 10^{-12} \, \frac{\text{As}}{\text{Vm}}$$.