Calculating Capacitance of a Spherical Capacitor based on Radius

The calculator will calculate the capacitance of a Sphere based on the given values Permittivity of Free Space (εo),Relative Permittivity (εr) and radius. Capacitances are the storage device for electrical charge.
Formula: C=4πεoεra
Where, C = Capacitance of Sphere, a = Radius, εo = Permittivity of Free Space, εr = Relative Permittivity
Permittivity of Free Space (εo): 
Relative Permittivity (εr): 
Capacitance of Sphere: F