Calculate the Capacitance between Parallel and Coaxial Circular Disks

The calculator will calculate the capacitance of parallel and coaxial cylinders based given values of a permittivity of free space, relative permittivity radius and distance.
Formula: C ≃ (εo εrπa2 / d) + εo εra * [ ln((16πa) / d)-1 ]
Where, C = Capacitance of Parallel and Coaxial Cylinders, a = Radius, d = Distance, εo = Permittivity of Free Space, εr = Relative Permittivity
Permittivity of Free Space (εo): Radius: 
Relative Permittivity (εr): Distance: 
Capacitance of Parallel and Coaxial Cylinders: F