Seamless Sweater Construction

When knitting seamless you’ll knit your sweater in one piece, you won’t have to sew anything together. And there are several methods to get there. In this blogpost you’ll learn about the differences of raglan shaping, round yoke construction and dropped sleeves. Also we’ll go through the pro’s and con’s of each construction method. 

The opposite of knitting in one piece is obviously to knit in pieces and sewing them together, which is not covered in this blogpost.

The basics of seamless sweater knitting

When knitting a sweater you can decide on knitting the sweater from the top down or bottom up. If you decide on knitting top down you’ll need increases to get from the neck circumference to the widest circumference needed. If your sweater is knit bottom up, you’ll need to decrease at some point, to get from the widest circumference to the neck circumference. 

So basically: it’s all about the increases and decreases.

We’ll go through examples for different construction methods in the following, for now know that you’ll need either increases or decreases to get that sweater shape. Or do you? Could there be a method without any increases or decreases?

Learn about:

The different sweater constructions: raglan,

1. Raglan Sweaters

Raglan Sweater

The name “Raglan” is based on the english Lord Raglan, who fought in the battle of Waterloo and had lost an arm. Therefore this special sleeve construction was created, to make it easier for the lord to dress himself.

In a raglan shaped garment the seam is parallel to the shoulder, so that a seam on top of the shoulder isn’t necessary. In the case of knitting the garment in one piece, the shaping of the shoulder happens through increases or decreases that form the four lines where otherwise the seams would be (two lines on the front and the same on the back)

Example, when knitting a sweater top down:

You start at the neckline and increase every second round (this is just an example, the increase rounds could vary). The increases are always placed in the same spots and there are exactly eight increases per increase round. You already learned that there are four lines, which means, you may have guessed: every line needs two increase spots, one before and one after the “line”. (Actually that line is created because of the placement of the increases.)

The goal here is to increase as many stitches to end up with enough stitches to at least cover the circumference of your chest plus the circumferences of both your upper arms.

Also, you want to get there in a certain amount of rounds to cover your yoke depth

After reaching that goal you’ll separate the sleeves from the body and knit them individually.

Example, when knitting bottom up:

It’s basically the same construction as the top down version, the main difference is that you knit the body starting at the hem and the sleeves beginning at the cuff, as separate parts first. When you’ve got all three parts ready to a certain point, you’ll join them in the round and knit the yoke in the end.

This time you’ll have to use decreases instead of increases to get to the wished neck circumference. The spots of the decreases are the same as for the increases.

Comparing the raglan construction to round yoke and dropped shoulder:


  • easy construction
  • easy to learn
  • good fit


  • not ideal for a colorwork yoke
  • not ideal for an all over yoke pattern, if you don’t want it to be interrupted by raglan lines.

Should you knit your raglan top down or bottom up?

It depends on the end result that you’re aiming for. Personally, I prefer knitting top down (any garment, any method), but there are pro’s and con’s to each:

Top down


  • easy to adjust in length
  • good for simple garment knitting
  • easy to add a little extra pattern to the raglan “line”


  • patterns in the yoke are a little harder to handle (because you have to wrap your brain around what the increased stitch should become – trust me, I’ve been there)

Bottom up


  • Easy when knitting a yoke pattern (you don’t have to think about the stitches as much, because you’re decreasing stitches that are already there) 


  • adjustments in length are nearly impossible after joining body and sleeves, there might be holes under the arms, where you joined body and sleeve.

2. Round yoke sweaters

In a round yoke sweater there aren’t any obvious “lines” that you’ll notice. You could say that this construction is truly seamless. Of course you’ll have to do the increases or decreases to get the number of stitches needed. As in the raglan construction there will be increase or decrease rounds, but those won’t be that visible in a line. Why is that, you ask? Because the increases/decreases are more spread out and there will be less increase/decrease rounds compared to a raglan construction. In the picture the increase/decrease rounds are made visible as drawn lines to show the possible position of the increase/decrease rounds. There are several other possibilities of placing them though!

Let’s dive into the example of knitting top down:

You start at the neckline and typically you’ll have the first increase round just a few rounds in, increasing 50% of your stitches. If you’re cast on was a 100 stitches an increase could look like this: K2, M1, meaning: knit two stitches, then make one stitch (one increased), to the end of the round. Then you’ll end up with 150 stitches on the needles (50 stitches increased). After the increase round you’ll have a couple of rounds without having to increase (depending on the pattern you’re knitting), followed by another increase round where you increase another, let’s say 25% of your stitches (this is just an example and could vary a lot, there are many possibilities!) and so on, until you end up with the needed stitches to cover at least the circumference of your chest plus the circumferences of both your upper arms (just as with the raglan). 

When knitting bottom up

The beginning is the same as in the raglan method: you knit the body and sleeves separately, bottom up first, then join them in the round. Instead of increasing you use decrease rounds now, but the method is the same as in the top down round yoke construction. 

Comparing the round yoke construction to raglan and dropped shoulder:


  • very good for a colorwork yoke and all over yoke pattern without interruptions
  • good fit


  • not ideal for simple garments (plain stockinette), because the increases/decreases will be visible and they will be all over the yoke

Should you knit your round yoke top down or bottom up?

It really depends on your preference. I, personally can’t think of a good reason why I would knit a round yoke bottom up and will always recommend knitting it top down, this way you can easily adjust body or sleeve length, if needed

3. Dropped shoulder sweater

Where the first two methods we took a glance at were very similar, the dropped shoulder construction differs. A simple T-shirt has a dropped shoulder construction, it usually sits a little loose on the body. 

Although I knit the garment in one piece, it felt more like a knitting in pieces than a raglan or a round yoke construction. And here’s the main difference: you could get away with a whole garment without having to increase or decrease anything. I don’t recommend that, I just wanted to say that it is possible.

Let’s see how this works, when knitting top down: 

Now, there are at least two possibilities where to begin the cast on:

The easier way: casting on the back, knitting to yoke depth, then picking up stitches for the front at the top, leaving an opening for the head.

The more complex way: Casting on the back, but using a “double” cast on method that will leave you with stitches on both sides, such as “Judy’s magic cast on”, so that you don’t have to pick up any stitches. This way you’ll have no visible “seam”. Of course you’ll have to leave an opening for the head here as well! 

No matter which way you choose, keep in mind that you might want to go for a more open neckline, in which case you’ll have to do increases. Then you’ll pick up stitches (in case of the easier way) for the front on either side of the neck and knit down each of them, increasing for the wished neckline (v-neck or round), joining the two front parts when ready.

In either case you knit the front and the back in rows on their own, until they reach at least yoke depth, then you’ll join them to the round. This way you create the armholes. After you finish knitting the body in the round you pick up the stitches for the sleeves around the armholes and knit each of those. 

Of course, as in any other sweater, you could add increases or decreases to shape the garment a little more, but it is possible to get away with very few increases/decreases.

Knitting bottom up:

You could knit the body part bottom up, but if you wanted to knit the sleeves bottom up as well, you’d have to sew them on in the end. So when knitting the body bottom up, I’d recommend knitting the sleeves top down (as described above). 

For the body: You cast on in the round at the hem, knitting to the point of yoke beginning (just below arm beginning), then you separate front from back and knit each in rows separately. For the back: knit to the top of the shoulders. For the front: you might consider splitting in half again for a more open neckline and using decreases to shape the neckline. Both parts are knit to the top of the shoulders and joined there using either a three-needle-bind-off or kitchener stitch.

Comparing the dropped shoulder construction to round yoke and raglan:


  • less increases/decreases,
  • (non-colorwork) patterns are easy to add
  • ideal for simple garments
  • good as a cardigan
  • loose fit


  • not ideal for colorwork, when knitting in rows
  • loose fit 

Should you knit your round yoke top down or bottom up?

Again: it really depends on your preference! It won’t be a surprise: I like knitting top down as it is easy to adjust body length, if needed. 

How do you choose the right sweater construction?

When you want to design your own sweater and are not sure what construction to use, think about what you want in the sweater, is it mostly colorwork that you’d like to knit? Is it a cabled pattern or a more simple garment? First get that clear then you could go through the pro’s and con‘s of the different constructions to make it more easy to choose. Basically, when I’m doing a colorwork yoke sweater, I choose the round yoke construction, for a simple knit with a little patterning, I choose a raglan and for a cardigan or a sweater with more positive ease, I like the dropped shoulder construction.

Hope this little overview helped, if you have any questions, please let me know!

Love, Sarah


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