What You Need to Start an Infinity Scarf

An infinity scarf is a loop with no beginning or end — you knit a rectangle, then join the two short ends together. The construction is simpler than it sounds: you cast on stitches, knit rows until the piece is long enough to wrap around your neck twice, then bind off and seam the ends. The whole project takes a weekend or two, depending on yarn weight and how often you knit.

You will need yarn (any weight works, though worsted or bulky finishes faster), needles sized to match your yarn, a tapestry needle for seaming, scissors, and a measuring tape. Check your yarn label for the recommended needle size — using the right size prevents the scarf from bunching or sagging. Most infinity scarves use between 200 and 400 yards of yarn, so a single skein often covers the whole project.

Key Takeaways

  • An infinity scarf is a rectangle knitted flat, then seamed at the short ends to form a loop.
  • Cast on 30 to 50 stitches depending on how wide you want the scarf, then knit every row in garter stitch until the piece measures 50 to 60 inches long.
  • Bind off all stitches, then use a tapestry needle and matching yarn to seam the two short ends together with a mattress stitch.
  • Bulky yarn finishes in one or two sittings; fingering-weight yarn takes longer but uses less yardage.

Choosing Yarn Weight and Needle Size

Yarn weight determines how fast your scarf grows and how much yardage you need. Bulky yarn (weight 6) knits the fastest — a finished scarf takes 200 to 250 yards and can be done in a few hours. Worsted weight (weight 4) is the middle ground, needing 250 to 350 yards and taking a weekend. Fingering weight (weight 1) is the slowest but uses the least yarn and creates a drapier, more delicate scarf.

Always check the yarn label for the recommended needle size. Using needles that are too small makes the scarf stiff and tight; too large makes it loose and floppy. If your yarn says "US 8–10 needles," pick the size in the middle of that range unless you knit very tightly (then go up one size) or very loosely (then go down one size). Needle material — bamboo, metal, or plastic — does not affect the scarf, so choose whatever feels comfortable in your hands.

Casting On and Planning Your Width

Cast on between 30 and 50 stitches, depending on how wide you want the scarf. Thirty stitches makes a narrow scarf about 4 inches wide; 50 stitches makes a fuller one about 8 inches wide. Most people prefer something in the middle — around 40 stitches — because it wraps well without being bulky at the neck.

Use a long-tail cast-on or any cast-on method you know well. The long-tail cast-on is popular because it creates an even edge that seams neatly. Count your stitches twice before you start knitting to avoid discovering a mistake three rows in. If you are new to cast-on, practice on scrap yarn first — a sloppy cast-on edge makes seaming harder later.

Knitting the Rectangle in Garter Stitch

Garter stitch — knitting every row — is the standard for infinity scarves because it lies flat, looks the same on both sides, and is forgiving if you make small mistakes. Knit every single row until your piece measures 50 to 60 inches long. Measure from the cast-on edge to your working yarn every 10 rows or so to stay on track.

The length matters because the scarf needs to wrap around your neck at least twice. If you are unsure, knit until the rectangle is about as long as your arm span — that is usually close enough. Once you bind off, you will lose a little length to the seam, so erring slightly long is safer than too short. If you run out of yarn before reaching 50 inches, you can still seam what you have, but the scarf will only wrap once.

Binding Off and Preparing to Seam

Bind off all stitches using a standard bind-off: knit two stitches, pass the first stitch over the second, knit one more stitch, pass the first over the second, and repeat until one stitch remains. Cut the yarn, leaving a 6-inch tail, and pull the tail through the last stitch to find it. Weave in the cast-on and bind-off tails using a tapestry needle, working them through nearby stitches on the wrong side of the scarf.

Before seaming, lay the rectangle flat and check that both short ends are straight and even. If one edge is wavy, you can gently block the scarf by pinning it to shape on a towel, misting it with water, and letting it dry — but this is optional for a casual scarf. Once the tails are woven in, you are ready to seam.

Seaming the Ends Together with Mattress Stitch

Mattress stitch is the best seam for this job because it is nearly invisible and creates a smooth join. Thread a tapestry needle with a length of matching yarn (about 24 inches). Hold the two short ends of the rectangle with their right sides facing you, edges touching. Insert the needle under the first stitch on the left edge of one end, then under the first stitch on the left edge of the other end, going back and forth between the two edges.

Work your way across the width of the scarf, picking up one stitch from each side in turn. After every few stitches, pull the yarn snug — not tight enough to pucker, but tight enough that the seam closes. Once you reach the far edge, weave the seaming yarn through nearby stitches on the wrong side and trim. The seam should be almost invisible from the outside, and the scarf should now form a complete loop.

Finishing and Wearing Your Scarf

Try on the scarf and check that it wraps comfortably around your neck twice without bunching. If the seam feels stiff or uncomfortable, gently massage it with your fingers to loosen it. You can also block the finished scarf by laying it flat, misting it lightly with water, and letting it dry to even out the texture and soften the seam.

Infinity scarves are durable if you knit them with care. Garter stitch does not unravel easily, and a solid seam holds through many wearings. Wash your scarf by hand in cool water with gentle soap, squeeze out excess water (do not wring), and lay it flat to dry. With basic care, a hand-knit infinity scarf lasts for years.

Frequently Asked Questions

Can I use a pattern instead of just garter stitch?

Yes. Ribbed stitch, seed stitch, or stockinette stitch all work, though stockinette curls at the edges unless you add a garter-stitch border. If you choose a stitch pattern, follow the pattern instructions for cast-on and bind-off, and measure your length the same way — 50 to 60 inches before seaming.

What if I run out of yarn before the scarf is long enough?

You can seam what you have, but the scarf will only wrap once instead of twice. Alternatively, you can pick up stitches along the bind-off edge and knit a second rectangle, then seam both pieces end-to-end before joining the final seam. This adds length without starting over.

How do I fix a dropped stitch while knitting?

If you drop a stitch, pick it up with a crochet hook by pulling the working yarn through the loop, working your way back up to the current row. If you do not catch it right away, you can fix it later by unraveling back to that point, picking up the stitch, and reknitting. For a beginner, it is often faster to just keep going — a small dropped stitch in garter stitch is hard to notice.

Do I have to seam the ends, or can I knit them together?

Seaming with mattress stitch is the standard method and creates the neatest join. You can also use a three-needle bind-off if you prefer, though it creates a thicker seam. Mattress stitch is easier for most knitters and looks better when worn.