How **SHOULD** a sweater fit?
Updated: Apr 12

Whenever we introduce ‘shoulds’ into art, I get a little itchy. It implies an objective metric for something subjective, right? At the same time, we throw the phrase ‘well-fitting’ around as if we all have a shared language and that it means the same thing for everyone. Let’s unpack it, y’all!
What is good fit?
For me, good fit means the garment is comfortable, functional, and doesn’t pull, ride up, or have drag lines, and has equal tension throughout the fabric.
In other words, it goes on, stays on, and matches the shape of your body appropriately for the ease in the garment.

What’s a drag line?
A drag line is a fold or wrinkle in the fabric. It shows a tension gradient, at one end of the line the fabric is being pulled too tight relative to the other end of the line. Generally, this means you need to add fabric to release tension.
In this picture of Local Meadow, the drag line runs from the bust (too tight) to the hip (enough room). That's happening because the dress form is padded to have a larger bust than the designer had in mind for this size body. We're gonna get into it!
Fit is subjective
We all agree that a sweater that won’t go over your head because the neckline is too tight doesn’t fit. But one person might love a big sloshy sweater that falls off the shoulder, while another considers that ill-fitting. For our purposes, it’s helpful to keep in mind that knitting is most satisfying when we can predict the end result. So as we evaluate fit, the real question we’re going to be answering is ‘how will this fit on MY body.’
Common fit issues
I talk to lots of knitters who know they aren’t happy with their fit, but don’t know exactly what it is they don’t like. Here are the top three issues I see, and what causes them.

1. You’re in the wrong size
When addressing fit issues, we need to fit our garments from the top down. That means getting a great fit in the shoulders, then the underarm, THEN the bust.
It’s unintuitive because we live in an extremely boob-centric media world, but our full bust line and most of the fullness of the breast is BENEATH the underarms. This is especially confusing for makers who think of garment construction through the lens of knitting (instead of sewing or tailoring, for example). Why? Most knitting patterns have us reach the full bust width AT the underarm. Think about all those raglans and yokes you’ve knit where you reach the full stitch count and then split for the underarm. No wonder we think of the full bust as an upper-torso measurement!
Most knitting patterns ask us to choose a size based on our full bust. Unfortunately, full bust is a poor predictor of the size of the rest of our torso. If you’ve learned the hard way that choosing based on full bust results in a sloppy fit in the neck, underarm, and shoulders, DO disregard that guidance and size down. On the other hand, if your knitting patterns end up tight in the underarms and across the upper chest, you probably have a smaller cup than expected for your size, and more of your full bust measurement is torso - you need to go up a garment size. Note: going down a size when you have a full bust may mean you have negative ease in the full bust. Solve this by adding short rows, or know that a little negative ease in the full bust (up to about an inch of negative ease) is NOT going to change the overall fit of your garment. You’ll still have the room you need in the sweater and the top will have a tidier fit - it will not result in a garment that’s tight.

2. Your bust and hip aren’t the same size
Almost no humans are the same size in the bust and the hip, and yet, most knitting patterns are knit from the underarm to the hip with no shaping. Pictured, you can see that just a little bit of gentle shaping, like that in Postscript, can create a fit that more closely matches bodies that are wider at the hip than the bust and ribs.
When we have less ease through the hip than we have in the rest of the torso, our garment can look like it’s straining across the fullness of our hip, making our hips look larger and more prominent than they are. It can also cause the garment to ride up, as the hem seeks a more narrow place on the body to rest. To fix this, assess how much ease you’ll have in your hip where the sweater ends. See how this compares to the intended ease at the full bust. As noted above, your actual ease in the bust may vary and that’s okay. But if the designer intended there to be 3” of positive ease at the bust, you’ll probably want to aim for 3” of ease in the hip. You can add those stitches in two shapes - either a-line or by working hip shaping. A-line shaping decreases evenly from the hem to the underarm. For hip shaping, work straight for several inches and then begin to taper. Hip shaping leaves the garment wider longer, and is great if you have a thicker waist.
3. You need bust shaping
Who needs bust shaping? Anyone who sees that the front hem of their garment is higher than the back hem when they look at a side photo of themselves.
In the photos below, I've knit the same garment twice (and this pattern won't be ready until April, so I'm sorry to be a tease, but it's such a good illustration of this fit issue I can't help it).
On the left, the purple sample clearly rides up in the front. You'll also see lots of drag marks and wrinkles in the fabric, because there is not enough room for the full bust.
On the right, I have the same size garment but with bust darts. The hem is parallel to the ground, there are no wrinkles or drag marks, and I can relax because I don't have to worry about where my sweater is going.
Is this a subjective fit issue? Or an objective fit issue?
Some people like to frame this as a high-low hem, and a style choice, but I disagree.
This will always look ill-fitting (to me) because there will be drag lines and wrinkles that make the garment look weird. That’s happening because there is not enough room at the bust, and it makes the underarm look bunched up. A high-low hem is a fine style choice, but all that weirdness on the side of my un-darted top? It's hard to say that's a style choice.
Furthermore, this fit issue can cause the garment to slide back, because the tension in the front holds up some of the weight of the garment. In comparison, the back of the garment is unsupported, and therefore heavier.
If you’d like to have a high-low hem, create one by changing the shape of the hem (make the garment shorter, then work short rows that exclude part of the front). If you're busty, do that AND add the shaping you need for your bust. You’ll have a garment that stays put and doesn’t bunch, drag, or get pulled to the back.