You can knit a beanie flat on straight needles and seam it closed

A beanie knit on two straight needles is made in one flat rectangle, then folded and sewn up the back and across the top. This method works because straight needles are easier to control than circular needles for many knitters, and you do not need to learn to work in the round. The finished beanie looks the same as one made on circular needles — the seam runs up the back of the head and is barely visible once worn.

The basic process is: cast on stitches, knit rows until the rectangle is tall enough to wrap around your head, bind off, then sew two seams. The whole project takes a weekend for most knitters and uses one ball of worsted-weight yarn.

Key Takeaways

  • Cast on 50 to 60 stitches in your chosen yarn weight and needle size, then knit every row in garter stitch until the rectangle measures 8 to 9 inches tall.
  • The width of your cast-on edge becomes the circumference of the beanie, so measure around your head or someone else's and add half an inch for seaming.
  • Bind off all stitches loosely so the top edge does not pucker, then thread a tapestry needle and sew the two short ends together with a mattress stitch.
  • Fold the tube in half and sew the top closed with a ladder stitch, which creates a flat seam that sits inside the hat.
  • Weave in all yarn ends before wearing, and block the finished beanie gently with steam if the edges curl.

Measure your head and choose yarn and needles

Measure around your head with a soft measuring tape, just above your ears and eyebrows. Write down that number — it is your target width. A typical adult head is 21 to 23 inches around; children's heads are 16 to 20 inches. Add half an inch to your measurement to account for the seam allowance.

Choose a yarn weight and needle size that work together. Worsted-weight yarn (also called medium or #4) and US size 8 to 10 needles are the easiest starting point. If you pick a different weight, check the yarn label for the recommended needle size. Thicker yarn and larger needles knit faster; thinner yarn and smaller needles take longer but create a denser, warmer hat.

Buy one ball of yarn if it weighs 100 grams or more. A standard 100-gram ball of worsted-weight yarn holds roughly 190 yards, which is enough for a beanie. If your yarn ball is smaller, buy two.

Cast on and knit the body in garter stitch

Cast on stitches using the long-tail cast-on or your preferred method. The number of stitches depends on your yarn weight and needle size, but a rough guide is: one stitch per quarter inch of width. If your head measures 22 inches around, cast on 88 stitches. For worsted weight on size 8 to 10 needles, cast on 50 to 60 stitches for an adult beanie.

Knit every row in garter stitch — knit stitches on both the right side and wrong side. This creates a textured, reversible fabric that does not curl at the edges. Garter stitch is the easiest stitch pattern for a beanie because you never have to purl or count complicated rows.

Knit rows until your rectangle measures 8 to 9 inches tall. Measure along the side edge with a ruler. The height should be roughly half your head circumference; this way, when you fold the rectangle in half and seam it, the finished beanie will fit snugly. If you are unsure, knit until the rectangle is 9 inches and try it on before binding off.

Bind off and prepare to seam

Bind off all stitches loosely using the standard bind-off method: 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 it through the last stitch to find it.

Bind off loosely so the top edge of the beanie does not pucker or pull tight. If your bind-off edge looks tight, you can use a needle one or two sizes larger just for the bind-off row — knit the row on your regular needles, then switch to the larger needle for binding off.

Thread a tapestry needle (a blunt needle with a large eye) with the yarn tail from your bind-off. You will use this to sew the first seam. If the tail is shorter than 12 inches, cut a new piece of yarn about 18 inches long and thread it instead.

Sew the back seam with mattress stitch

Lay your rectangle flat. The two short ends are the sides of the beanie; you will sew these together first. Hold the rectangle so the cast-on edge is at the bottom and the bind-off edge is at the top.

Bring the two short ends toward each other so the right sides of the fabric face outward. This is called mattress stitch — you sew from the inside so the seam is hidden. Insert the tapestry needle under the first stitch on one edge, then under the first stitch on the opposite edge, going back and forth between the two edges. Pull the yarn snug every few stitches so the seam closes.

Sew all the way up the back seam until the two ends meet. You now have a tube. Weave the yarn tail through the last few stitches on the inside and trim it.

Close the top with a ladder stitch

Fold the tube in half so the back seam runs up the middle. The bind-off edge is now at the top and forms an open edge. Thread the tapestry needle with a new 18-inch length of yarn.

Use a ladder stitch to close the top. This stitch creates a flat seam that sits inside the hat. Insert the needle through one stitch on the left side of the opening, then through the opposite stitch on the right side, going back and forth. After every two or three stitches, pull the yarn snug so the opening closes. The seam will disappear inside the fold.

Sew until the opening is closed, then weave the yarn tail through the last few stitches and trim it. Turn the beanie right-side out and try it on.

Finish and block if needed

Weave in any remaining yarn ends with the tapestry needle, working them through the stitches on the inside of the hat so they do not show. Trim the ends close to the fabric.

If the edges of your beanie curl or the fabric looks uneven, you can block it gently. Fill a sink with cool water and a small amount of wool wash (or mild dish soap). Soak the beanie for 10 minutes, squeeze out the water gently, and lay it flat on a towel to dry. You can shape it around a bowl or your head while it dries to set the fit. This step is optional but makes the beanie look more finished.

Frequently Asked Questions

What if my beanie is too loose or too tight?

Looseness or tightness comes from the width of your cast-on edge. If the beanie is too loose, you cast on too many stitches. Next time, cast on 5 to 10 fewer stitches. If it is too tight, cast on more. You can also adjust the fit by blocking: wet the beanie and stretch it gently to the size you want, then let it dry flat.

Can I use circular needles instead of straight needles?

Yes. If you switch to circular needles, you can knit the beanie in the round instead of flat. Cast on the same number of stitches, join them in a circle, and knit in the round until the beanie is tall enough. Bind off and weave in the ends — no seaming needed. The method in this guide works with straight needles only.

How do I fix a dropped stitch?

If you drop a stitch while knitting, pick it up with a crochet hook before you go too far. Insert the hook through the dropped stitch from front to back, catch the horizontal strand of yarn above it, and pull it through. Repeat for each row above the dropped stitch until the stitch is back on your needle.

What yarn weight makes the warmest beanie?

Bulky or super-bulky yarn (sizes #5 and #6) creates a thicker, warmer beanie than worsted weight. Bulky yarn also knits faster. The trade-off is that bulky yarn uses more yardage, so you may need two balls. Worsted weight is a good middle ground for warmth and yarn economy.

Do I need to block my beanie?

Blocking is optional but recommended. It evens out uneven stitches, sets the shape, and makes the beanie look more polished. If your edges curl or your stitches look loose, blocking with steam or wet blocking will improve the finish. If your beanie looks even and you like the fit, you can skip this step.