Pondering the math. And boobs

By Megan Goodacre

Pondering the math. And boobs

I'm in the process of grading a woman's pullover pattern. And, as usual, spending a lot of time tweaking (not to be confused with the ubiquitous "twerking") the neck circumference.

This is a tricky measurement to grade. How big should the neck opening on a pullover be? It has to be big enough to go over the wearer's head. It has to be small enough to cover the bra straps. But the pattern also has to cover a broad range of sizes: from a 32 to 64 inch bust. The gamut of body types that will fall in that range… well it boggles the mind.

Side note: should knitting patterns include every size? Or should they go the way of sewing patterns, where you pick a small range close to your own size? Annoying if you want to make something for a bunch of differently sized people, but better for following and writing surely?

Anyways. The math. EZ famously described a percentage system for sweaters. You start with the body circumference, and everything is a ratio of that measurement. (The neck is 40% of the body, a long sleeve cuff is 20% of the body, etc). The percentage system is a wonderful concept, and you can see that it works (much of the time) for (many) knitters.

But clothing isn't about measurements. Oh yes, the math is very important. But if all clothing were based on a single ratio system, style would never change. There would be no "style", just degrees of fit. We'd all dress in futuristic one-piece jumpsuits or large tents.

So. Neck ratio. When I have a question about garment measurements, I do a little spying. I'll measure sweaters from the Gap, look at knitting magazines, read old knitting books, and start comparing. And the numbers are often surprising.

Many sweater designers appear to rely on the EZ formula (neck = 40% of chest in a round neck pullover).

But here's my issue with the neck as ratio of the chest. In adults, the measurement with the biggest difference is the chest. Other measurements have surprisingly little variation (arm length or the cross-back for example). According to the Craft Council, the difference from the smallest bust to the largest bust is about 32 inches. But the difference from the smallest cross-back to the largest is only 4 inches. That means a lot of the difference in the chest circumference is not evenly distributed around the body; a lot of it is, well, in the boobs (which makes sense).

Since the neck (regardless of your cup size) is pretty boob-free, I think it's more related to the cross-back than it is to the bust measurement. And, I don't think a constant ratio (e.g. 40%) is finely enough tuned. For example, 40% of an extra small 32 inch bust sweater is only 12.8 inches. Considering the average 3-year old has a head about 18 inches around, and that a choker necklace is about 16 inches, that's a very small neckline. To be clear, I'm not critiquing EZ here; she was writing before the (fairly) recent trend of sizing patterns for petite and plus sizes.

I think the 40% ratio works nicely for men's sweaters that are small to large. Men's round neck sweaters are usually styled to cover the clavicle and come to base of the Adam's apple, so a snug(ish) neckline is suitable. Women's round neck sweaters can hit a little lower, revealing part of the clavicle, so a larger ratio like 45-48%, might work for average sizes. But the sizes on either end of the scale need some tweaking.

I have to get back to my spreadsheets now, but here's a thought:

What if the neck size, for either men or women's sweaters, used the ratio of cross-back to chest, and then had ease added to it? For men's, a round neck would have a small or negative amount of ease, while women's would have more. I think I might be on to something…

Here are some quick sample numbers using this idea:

(Women) Finished Bust 32 40 48 60
Cross back 14 15.25 16.25 18
Ratio of cross back to (actual) bust 44% 38% 34% 30%
Calculated base neck opening using ratio 14.00 15.25 16.25 18.00
Ease 5 5 5 5
Neck opening with ease 19.00 20.25 21.25 23.00
(Men) Finished Chest 38 42 52 56
Cross back 15.5 16.5 18.5 19
Ratio of cross back to (actual) chest 41% 39% 36% 34%
Calculated base neck opening using ratio 15.50 16.50 18.50 19.00
Ease -0.5 -0.5 -0.5 -0.5
Neck opening with ease 15.00 16.00 18.00 18.50