How to Knit a Raglan Sweater Top Down (Any Size!) — Knit a Sweater With Me ✨
There is something genuinely magical about casting on at the neckline of a sweater and watching the whole garment grow in your hands, down toward the hem, without a single seam to sew at the end. Top-down raglan construction is one of the most beginner-friendly sweater methods in all of knitting, and it is also endlessly customizable — which means you can use it to knit a sweater in any size, for any body, from a cozy toddler pullover to a generous oversized adult fit. If you have been wanting to knit your first sweater, or if you have knitted sweaters before but struggled with sizing, this is the tutorial for you.
Pull up a chair, grab your yarn and needles, and let’s knit a sweater together.
What Is a Top-Down Raglan Sweater?
A raglan sweater is identified by its distinctive diagonal seam lines that run from the underarm up to the neckline. Instead of attaching separate set-in sleeves, the body and sleeves are joined at four increase points that create those characteristic diagonal lines. In a top-down raglan, you begin at the collar, work increases to shape the yoke, then separate the sleeves from the body and knit each piece down to the hem. The beauty of this method is that you can try the sweater on as you go, adjust the length freely, and avoid almost all finishing work.
This method works in the round on circular needles, which means you will have a seamless, comfortable fabric with no awkward side seams pressing into you while you wear it.
Supplies You Will Need
Before you cast on, gather everything you need so the process flows smoothly.
Yarn: Choose a yarn appropriate for the weight you want. Worsted weight is the friendliest for beginners because it knits up quickly and the stitches are easy to see. DK and sport weight produce a lighter, drapier fabric. Bulky weight is the fastest but gives less drape. You will need roughly 1,000–1,400 yards for an adult medium in worsted weight, though heavier sizes or longer bodies will need more. Always buy a little extra — running out mid-project is genuinely heartbreaking.
Needles: You will need a 32-inch or 40-inch circular needle in a size appropriate for your yarn. Check the yarn label for the recommended needle size, then swatch (more on that in a moment). You will also want a set of double-pointed needles (DPNs) or a second shorter circular in the same size for knitting the sleeves in the round once they are separated from the body.
Other tools: stitch markers (at least 4, plus a few extras), a tapestry needle, scissors, a measuring tape, and stitch holders or waste yarn for holding sleeve stitches.
Understanding Gauge — Don’t Skip This Part
Gauge is the number of stitches and rows you get per inch with your chosen yarn, needles, and personal knitting tension. It is the single most important factor in getting a sweater that fits, and skipping it is the number one reason knitters end up with a sweater that is three sizes too big or too small.
To check your gauge, knit a swatch at least 6 inches square in stockinette stitch. Wash and block the swatch the same way you plan to wash the finished sweater, because some yarns change size dramatically after washing. Then lay it flat, pin it lightly, and count the number of stitches over 4 inches. Divide by 4 to get your stitches per inch.
Write this number down. Every calculation in this tutorial will use it.
For the purposes of walking through the math, this tutorial will use an example gauge of 5 stitches per inch and a 4.5 rows per inch. Substitute your own numbers wherever you see these.
How to Calculate Your Sweater Size (the Any-Size Formula)
This is where top-down raglans shine. You do not need a pattern that happens to include your size — you calculate the numbers yourself from a handful of body measurements.
Grab your measuring tape and write down the following:
Chest circumference: Measure around the fullest part of your chest. Add 2–4 inches of ease depending on how fitted you want the sweater. A standard comfortable fit uses about 2 inches of positive ease. An oversized sweater might use 6 or more inches of ease.
Body length: Measure from just below your armpit to where you want the hem to fall.
Sleeve length: Measure from your underarm to your wrist.
Yoke depth: This is the vertical distance from the base of the neck to the underarm. For most adult sweaters this falls between 7 and 9 inches. You can measure a ready-to-wear sweater you like for reference.
Upper arm circumference: Measure around the fullest part of your upper arm and add 1–2 inches of ease.
Once you have these measurements, multiply each one by your stitch gauge to get stitch counts. Let’s walk through the example together.
Say your desired chest circumference with ease is 42 inches. At 5 stitches per inch, you need 210 stitches for the body in the round.
Your desired upper arm circumference with ease is 14 inches. At 5 stitches per inch, each sleeve needs 70 stitches at its widest point before separation.
Setting Up the Yoke
A top-down raglan begins with a provisional or long-tail cast on at the neckline. You will cast on the neckline stitches and immediately place markers to divide them into four sections: the back, the two sleeves, and the front.
Calculating your cast-on: A typical adult neckline is about 18–20 inches in circumference (loosely measured). At 5 stitches per inch and a 19-inch neck opening, that is 95 stitches. These are divided roughly as follows:
Back stitches: approximately 36% of total — roughly 34 stitches
Front stitches: approximately 30% of total — roughly 29 stitches
Each sleeve: approximately 17% of total — roughly 16 stitches each
Raglan “seam” stitches: 1 stitch at each of the 4 raglan lines — 4 stitches
Total: 34 + 29 + 16 + 16 + 4 = 99 stitches (adjust by a stitch or two to make the neck opening feel right — these are starting points, not absolutes)
Cast on this number, join to work in the round being careful not to twist, and place markers to separate each section. Your four raglan markers divide back / sleeve / front / sleeve. The single stitch between each marker is your raglan seam stitch and is typically knit as a plain knit stitch.
Working the Raglan Increases
The yoke is built by working increases on either side of each raglan seam stitch every right-side round (or every other round). The most common increase pair used here is a Make 1 Left (M1L) before the seam stitch and a Make 1 Right (M1R) after it, which gives a clean, nearly invisible increase that leans with the raglan line.
Each increase round adds 8 stitches total — 2 stitches per raglan point, times 4 points.
You will work increase rounds and plain rounds alternately until the yoke reaches your desired depth and the sleeve and body stitch counts reach the numbers you calculated above.
How many increase rounds do you need?
Going back to the example: the body needs 210 stitches in the round. The back currently has 34 stitches and the front has 29 stitches (total body = 63 stitches). You need to reach 210 body stitches. The increase rounds add 2 stitches to the front and 2 to the back each time (4 body stitches per increase round). So:
(210 − 63) ÷ 4 = 36.75, round up to 37 increase rounds
Check that the sleeves also reach the right stitch count. Each sleeve starts at 16 stitches and gains 2 stitches per increase round. After 37 rounds: 16 + (2 × 37) = 90 stitches per sleeve. But the target was 70 stitches. In this case you may need to work some rounds where you only increase for the body and not the sleeves — this is called a “body-only increase round” and it is a normal and common adjustment in top-down knitting.
Alternatively, you adjust your yoke depth expectations. This interplay between numbers is normal. Work through the math, see which piece reaches its target first, and adjust accordingly. Many knitters also simply try the sweater on at this stage, hold the sleeve stitches on waste yarn temporarily, and see whether the yoke looks right on their body.
Separating the Sleeves
Once the yoke is complete, it is time for one of the most satisfying moments in sweater knitting: separating the sleeves from the body.
To do this, knit to the first sleeve section and place those stitches on a piece of waste yarn or a stitch holder. Cast on a small number of underarm stitches (usually 4–10 stitches depending on the sweater size) using a backward loop cast on, then continue knitting across the front to the second sleeve section, place those stitches on waste yarn as well, cast on the same number of underarm stitches, and continue to the end of the round.
You are now knitting only the body stitches plus the underarm cast-on stitches. The sleeve stitches will wait patiently on their holders.
Why cast on underarm stitches? These bridge the gap under your arm and give the sleeve a more comfortable, rounded shape. The number you use depends on the sweater — for a standard fitted sweater, 6–8 stitches is common.
Knitting the Body
With the sleeves set aside, the body knits up fast. You are simply working in the round in stockinette (knit every round) or whatever stitch pattern you like — seed stitch, ribbing stripes, or even cables if you are feeling adventurous — until the body reaches your desired length from underarm to hem.
Measure your work-in-progress against yourself regularly. This is the joy of top-down knitting.
When you have about 2 inches left to the hem, switch to your chosen hem stitch. A 2×2 ribbing (knit 2, purl 2) is classic and stretchy. 1×1 ribbing (knit 1, purl 1) is neat and close-fitting. Seed stitch or a rolled stockinette hem are lovely alternatives. Work the hem for 1.5–3 inches, then bind off loosely. A stretchy bind-off like the Jeny’s Surprisingly Stretchy Bind Off is a wonderful choice for a hem that does not constrict.
Knitting the Sleeves
Return the held stitches for one sleeve to your needles. Pick up the underarm cast-on stitches and join to work in the round. You will now work the sleeve from the underarm down to the cuff.
Sleeves are tapered — they are wider at the upper arm and narrower at the wrist. To achieve this, work decrease rounds periodically throughout the sleeve. A common approach is to work a decrease round (k1, ssk, knit to 3 stitches before end, k2tog, k1) every 6th or 8th round until you reach your target wrist circumference.
Calculating sleeve decreases: If the sleeve has 70 stitches at the underarm and your wrist at 5 stitches per inch with 1 inch of ease is 8 inches (40 stitches), you need to decrease by 30 stitches total, or 15 decrease rounds (each removes 2 stitches). At a rate of every 7th round, that is 105 rounds of sleeve length. At 4.5 rows per inch, that is about 23 inches — which may be close to or slightly longer than your measured sleeve length. Adjust the frequency of decrease rounds as needed.
When the sleeve reaches the desired length, work a ribbed cuff and bind off as you did for the body. Repeat for the second sleeve.
Finishing Touches
Once both sleeves are done, weave in all your ends with a tapestry needle, closing up any small holes at the underarms and tidying everything neatly. Block your sweater by soaking it in cool water with a little wool wash, pressing out the excess water in a towel, and laying it flat to dry in your desired measurements. Blocking transforms knitting — stitches even out, the fabric relaxes and drapes, and the whole thing looks professional and polished.
If you want, add a neat button band, pockets, or any other embellishments at this stage.
Tips for Getting the Best Results
Swatch, block your swatch, then swatch again if your gauge is still off. Gauge changes after washing, and a sweater-quantity of yarn washes quite differently than a small square. Adjust needle size up or down if needed.
Use stitch markers generously. Beyond the four raglan markers, place markers every 20 or 30 stitches on long rounds so you do not lose your place.
Try it on constantly. The absolute best thing about top-down construction is that you can slide the stitches to the cord of your circular needle and try the sweater on your body at any point. Do this often. Knitting to a specific row count and trusting that it will fit is much more stressful than just checking.
Keep a notes page. Write down what increase round you stopped at, how many underarm stitches you cast on, and how many decrease rounds you worked on the first sleeve before you start the second one. This avoids the dreaded “second sleeve syndrome” where you cannot remember what you did and the sleeves end up different lengths.
Customize freely. Once you understand the architecture of this sweater, you can change almost anything: add a wider neck, turn the pullover into a cardigan by working back and forth with a steek or front opening, work colorwork bands on the yoke, or add textured stitches to the body. The top-down raglan is a framework, not a cage.
Troubleshooting Common Problems
The neckline is too tight: Cast on more stitches next time, or use a larger needle for the cast-on row only. A stretchy cast-on like the long-tail method generally works well for necklines.
The yoke looks puckered or stiff: This often happens when increases are worked too tightly. Try a larger needle for the yoke section, or switch to a paired increase method that creates more ease.
There are holes at the underarms: This is normal and easy to fix during finishing. When you weave in ends, use the tail to close any gaps neatly, or pick up an extra stitch at the underarm and decrease it away on the next round.
The sleeves are too long: No problem — you can rip back from the cuff upward and re-knit to a shorter length. This is another advantage of working top-down.
The body is too short: Again, easily fixed. Rip back the hem, add more length, then re-work the hem. Far easier than trying to add length to a bottom-up sweater.
You Can Do This
Knitting a sweater from scratch sounds intimidating until you realize that it is just one round at a time. The top-down raglan method breaks the whole project into very manageable steps: cast on and set up markers, increase every other round until the yoke is done, separate the sleeves and knit the body down, knit the sleeves down, block everything. That is the whole sweater.
The math looks complicated laid out in a tutorial like this, but in practice you run through it once on a piece of paper before you begin, write down your numbers, and then you simply knit to those numbers. The needles do not know that you spent twenty minutes figuring out how many increase rounds to work — they just feel the yarn and make loops.
Take your time. Enjoy the process. And when you finally cast off that last stitch, wash your sweater, block it flat, and put it on for the first time — there is no feeling quite like wearing something you made with your own hands, calculated to fit your own body, in a color you chose for yourself.
Now go cast on. You have got this. ✨
