How to knit a great-fitting sweater

the Set-In Sleeve edition, part 1 :)

Many knitters are familiar with working a round yoke (I talked about these here) or a raglan sleeve sweater. And a great strategy to help you decide what size to make is to take a look at the bust size first.

A designer will usually (hopefully!) put in their recommendation for ease (“choose a size that is 2-3” bigger than your bust measurement,” for example), and you can make your decision from there.

But when it comes to knitting a set-in sleeve sweater, it’s a slightly different beast! Sure, bust size is very important, but there are other measurements to consider as well:

The first of these is your “crossback” (shown by the blue arrow above). Yes, it can be measured across your front, but it’s generally easier to get an accurate measurement across your back.

It’s not the same as your shoulder-to-shoulder measurement, and it’s not half your bust measurement—the crossback only measures across your back from your left “arm break” to your right “arm break”. It doesn’t include your underarms at all.

On the garment, it is the distance between the two set-in sleeve seams that go down the back of the bodice:

I recommend for all of my set-in sleeve patterns (like this one) that you begin with a size that has a crossback measurement that closely matches your own. Fit your crossback, and you begin to fit your frame.

Too wide a crossback, and the sweater will be falling over your shoulder line (might as well do a drop-shoulder instead!). Too small of a crossback, and it’s going to be uncomfortable no matter what size you make the bust.

So how do you find this measurement on yourself?

It’s probably easiest to have someone else take this measurement on you—unless you’re like me and enjoy contorting your body like it’s a game of Twister and throwing your back out (don’t try it at home, kids…).

But another way is to find a set-in sleeve sweater that fits you well, and measure from sleeve-seam to sleeve-seam across the back. Like in the photo of the yellow sweater above.

Keep in mind that a lot of off-the-rack set-in sleeve sweaters tend to have a fairly wide crossback—this is because manufacturers are trying to fit as many different bodies as possible for a specific bust measurement. And while it’s possible to put a too-wide crossback onto someone with smaller shoulders, you can’t fit a too-narrow crossback onto someone with a wider back.

So be sure to compare the sweater measurement to your actual crossback.

We’ll talk about another important set-in sleeve measurement next time! In the meantime, you can always drop a comment on this post on Substack if you have any questions!

And if you’re looking for an easy summer knit that’s not a sweater, I’ve released a fun shawl pattern on Ravelry, this week:

Fans of The Muppet Shawl will recognize the stitch pattern from the Dr. Teeth section of the mkal—it’s a super cute stitch that looks way more complicated than it is—and a great way to use 2 skeins of fingeringweight yarn.

It’s on sale for a bit, so you can get to the details here:

That’s all for now! As always, it’s an honor to be in your inbox and share knitting thoughts with you. I hope you find it helpful—and mostly, I hope that you’re having a wonderful summer.

Happy knitting,

Mary (aka Lyrical Knits)