Aspect Ratio Revisited: Deja Vu All Over Again?

I know. I've already gone over aspect ratio. Maybe I'm just getting monotonous. Or, just maybe, some folks understand something better when explained in a different way. I mean, far be it from me to question the motives of my high-school math instructor's teaching methods.
I don't know about you, but I'm a "visual" learner. Always have been. You can give me the most eloquent explanation of how something is done but it will stick much better in my mind if it's shown to me. So, for those that are still confused about aspect ratio, I'm going to walk you through an example. Grab a cup of coffee, take a deep breath and keep reading...

Problem:

You've found a chainmaille pattern that you MUST try. The pattern calls for 20 gauge 2.5mm inner diameter rings. However, you - being the slightly more flamboyant being that you are, would much rather have it in 18 gauge wire. Simple, except - OH NO! The pattern never gives the aspect ratio!! Now what?!
Take comfort. We can find the aspect ratio with the information that we already DO know.
Now, 20 gauge wire (assuming we are going by American Wire Gauge measurements - and we are) is about .032 inches in diameter or, if you prefer, .81 millimeters. You can get the mm equivalent from the decimal inch measurement by multiplying the decimal inch measurement by 25.4(there are 25.4 millimeters in an inch):

.032 x 25.4 = .8128

Conversely, if you need to know the decimal inch measurement and only have the measurement in millimeters, then divide .8128 by 25.4:

.8128 / 25.4 = .032

Since the inner diameter of our pattern's rings is in millimeters, we'll use the metric measurement of our wire. We will take the .81mm of our 20 gauge wire and divide it into the inner diameter of the rings in our chainmaille pattern. So,

2.5mm (ring inner diameter) / .81mm (20 gauge wire diameter) = 3.0864197.

There you have it! The aspect ratio of the rings in your pattern is 3.09 (rounding up).

To find the inner diameter of your new rings in 18 gauge wire, take 18 gauge wire diameter (.040 decimal inch/1.02mm) and multiply it by the aspect ratio.

3.09 (aspect ratio) x 1.02mm (18 gauge mm thickness) = 3.15mm.

Your new 18 gauge rings should have an inner diameter of 3.15mm to make your chainmaille pattern.

To review:
- To get millimeter measurement from decimal inch measurement, multiply the decimal inch measurement by 25.4.
- To find the decimal inch measurement from millimeter measurement, divide the millimeter measurement by 25.4.
- There are 25.4 millimeters to an inch.
- Aspect ratio can be found by taking the ring inner diameter measurement and dividing it by the wire gauge thickness measurement of a pattern or chain you already have whereby you know at least the gauge of the wire and the inner diameter of the rings of said chain or pattern.
- Inner diameter measurement can be found by multiplying the aspect ratio by the wire gauge thickness measurement of the wire you intend to use.

Remember! Always wind a few rings and test them out first before winding up a large amount of your wire. Aspect ratios are in ranges, wire thicknesses vary slightly and sometimes a slightly smaller or slightly larger ring gives a better result.

If you still have questions, post a comment/question and I'll try to go over it again in another way.

Happy weaving!