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Most professional engineers and technicians will never have the need to calculate the capacitance, inductance, or impedance of a coaxial cable since they are usually designing systems using welldefined components that are manufactured to exacting specifications. Students, hobbyists (Ham radio operators), and research types are probably the ones most likely to actually plug numbers into a calculator. For those people, I present these equations.
Braided Flexible Coax 
SemiRigid Coax 
Capacitance (C) 
, where a = outside radius of inner b = inside radius of outer c = speed of light in a vacuum ε = dielectric constant = ε_{0} * ε_{r} ε_{0} = permittivity of free space ε_{r} = relative dielectric constant μ_{r} = relative permeability 
Note: a and b can be in any units of length as long as they are both the same. 

Inductance (L)  
Note: a and b can be in any units of length as long as they are both the same. However, l must be in the units shown. 

Impedance (Z_{0})  
Note: a and b can be in any units of length as long as they are both the same. L has units of Farads and C has units of Henries. 

Speed of Light (%c)  
Note: V has the same length units as c. 

Cutoff Frequency  
Note: a and b must be in units of length shown. 

Reflection Coefficient & VSWR  
Note: Γ is unitless. VSWR is written as a VSWR:1 ratio. 

Coaxial Cable Attenuation  
Cable attenuation is the sum of the conductor losses and the dielectric losses per the following equations.
Note: While reworking this page I was able to confirm all equations with original sources except these two, so use them with caution. I cannot recall where I got them. 
, where a = outside diameter of inner b = inside diameter of outer f = frequency (GHz) Z = impedance (Ω) tan(δ) = loss tangent ε_{r} = relative dielectric constant ρ_{ra} = inner conductor material ρ_{rb} = outer conductor material Note:
ρ_{r} = 1 for copper, 
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