Choosing a size: Set-in sleeve edition

Regardless of how you’d like your sweater to fit, I suggest that you start by choosing a size that fits your shoulders well.

Yes, you may then need to adjust the fit of the bust, waist, and/or hips – but trust me. Doing so is simpler than re-working the shoulders! And bonus, torso shaping is worked in the same way no matter how the sweater is knit, so your adjustments will always be the same. Since patterns are sized by full bust circumferences, you’ll need a way to tell which bust size will fit your shoulders well.

Upper Torso

Begin by taking a circumference of your torso all the way up where your armpits are. I call this the “upper torso”.

Upper-Torso-Measurements-square finished bust = upper torso + 0-3'' of ease
Once you’ve got your upper torso, choose a size as if that were the fullest part of your bust. For a set-in sleeve, I recommend adding 0-3”/7.5 cm to your upper torso, and choosing the finished bust size closest to the result.

This will give you a sweater that fits the way you want it to fit in the shoulders. Contrast what happens when I choose a size with zero ease in the fullest part of my bust – the traditional way of choosing a size:


With what happens when I choose a size based on my upper torso instead:


The first looks strange – the tailoring of the set-in sleeves is at odds with the bathrobe-like fit. The second looks appropriate for the sweater’s construction.

Different Fits

We wear all different kinds of sweaters – and how much room you’ll add to your upper torso depends on how many layers you’d like to wear underneath, and what look you’re going for. Set-in sleeve garments are the most tailored-looking construction, and so require the least amount of ease to fit well. I recommend three general ranges:

Close fit sweaters have 0 – 1” / 2.5 cm of ease and are intended to be worn next to the skin, or over one thin layer. They should never feel tight, but neither should they offer enough room in the shoulder area for a thick layer. Here are some examples:


Average fit sweaters have 1-2” / 2.5 – 5 cm of ease and are a great place for most people to start. They’ll offer enough room for a solid under-layer, and skim the body without clinging. Here are some examples:


Relaxed fit sweaters have 2 – 3” / 5 – 7.5 cm of ease and are great choices for when you’d like to wear your sweater as outerwear, or you’re looking for a slightly more slouchy look. They’ll accommodate a substantial underlayer and will be larger than your body everywhere. Here are some examples:


Fitting from there

Once you have a base size that fits your shoulders well, compare your body’s measurements to the base size to identify the modifications you’ll need. For example:

  • Bustier women may need to add width to the front bust
  • Women with larger hips may need to add width to the front and back hips
  • Women who carry most of their volume on their front, in the bust and belly, may need to add width to the entire front of their garment

And don’t worry! Making these adjustments is pretty simple. You can do it by hand, if you like – my Craftsy class Sweater Modifications for a Custom Fit teaches you how, step-by-step. Or, let the computer do all of the work by using my CustomFit custom sweater pattern generator.

titleCard customfit-card-for-ahd-blog
However you make your sweater pattern, having a great fit in the shoulders will give you a garment you wear day-in and day-out, in comfort and style.


Happy knitting!