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Re: I am a european!



Hi Sarah,

> What's the formula for wire gauge to mm conversion? Where n = the wire
> gauge, I tried 25.4/n and n * 0.001 as guesses - neither of these came out
> as below.
>
> Sarah

I had some trouble with this to at one time and went though excrutiating pain
to figure it out (I am not a math wiz). To go from either mm or inches to
"awg" size is not a linear function, it is a logrithmic function. Anyway,
here's what I came up with and it works for me - btw, if you have Excel on
your computer, then you can just pop it into a cell - that's what I use.

Inches to mm = inches * 25.4
mm to inchs = mm / 25.4

I use inches and convert that to awg size with the following formula:

AWG = -8.62448720299999 * LOG(inches / 0.324557964 , 2.718281829)

This is what you would put into a cell in Excel. The " , 2.718281829" is the
logbase value that the logrithimic function is to use. How I entered it about
is how you would enter it into Excel (without the "AWG" of course). Set the
cell to round to 1 decimal place and "Presto-Chango".

Example:

For a wire size diameter in inches of 0.0403:
AWG = -8.62448720299999 * LOG(0.0403 / 0.324557964 , 2.718281829) = 17.99688
this rounds to 18 awg.

For a wire size of 0.0159, this formula gives 26.01185 rounding to 26awg.

How accurate is this? Try 0.0031. Formula says 40.11741 rounding to 40awg.

The "inches" values I used were from a standard wire table for these awg sizes
(bare wire size of course).

Maybe someone will have something else out there, but this is my own little
nutsy formula. Hope it helps.

Take care,
Bart