Why is my calculated copper resistance for #6 AWG four times too low?

[satchmo05]

Hey all,

I am looking at the American Wire Gauge chart listed on Wiki ([PLAIN]http://en.wikipedia.org/wiki/American_wire_gauge).[/PLAIN] I am attempting to determine how they are getting their copper resistance values.

From my education, DC resistance is equal to [length/(conductivity*pi*radius of wire²)]. For example, if I am using #6 AWG - radius is equal to 4.115[mm], conductivity of copper is equal to 5.96e7[S/m]. This gives me 0.3154[mOhm/m], nearly four times smaller than the accepted value of 1.3[mOhm/m].

Where am I going wrong? Thanks,

- Satchmo05

 

[AlephZero]

For example, if I am using #6 AWG - radius is equal to 4.115[mm]...

Where am I going wrong?

The diameter is 4.115mm, not the radius. http://en.wikipedia.org/wiki/American_wire_gauge

 

[satchmo05]

Oh wow, that's embarrassing. Thanks for the second set of eyes. I've been staring at that very simple equation for 20 minutes and I just couldn't get anywhere. Most appreciated.