Coaxial cable is a common transmission line structure and most RF cables are coaxial cables. The impedance of a coaxial cable is the relationship between the capacitance per unit length and the inductance per unit length. This tool will help you find the inductance for a given length of coaxial cable.

Coaxial Inductance Explanation

It may be useful to understand the inductance of a coaxial cable. The variables required to calculate this inductance are the center conductor diameter, the distance to the outer shield, and the length. You may notice that the diameter of the outer shield is not required. It is assumed that the shield is thick enough. This calculation is for loop inductance where the outer shield is the return path for the center conductor.