Knitting a hat in the round means working in a spiral instead of back and forth

A hat knitted in the round has no seam running up the back because you never turn your work. You cast on stitches around a circular needle or set of double-pointed needles, then knit continuously in one direction until the hat reaches the crown. The fabric naturally forms a tube. This method is faster than knitting flat and sewing a seam, and the finished hat sits more smoothly on the head.

You will need either a 16-inch circular needle (for most adult heads) or a set of four or five double-pointed needles in the same size. The needle size depends on your yarn weight and the stitch pattern you choose. A basic stockinette hat in worsted weight yarn typically uses US 6 to US 8 needles.

Key Takeaways

  • Cast on an even number of stitches (usually 80 to 100 for an adult hat) and join them in a circle without twisting.
  • Knit in stockinette stitch (knit every round) until the hat reaches just below the ears, then begin decreasing for the crown.
  • Decrease stitches evenly spaced around the hat every other round until you have 8 to 10 stitches left, then cut the yarn and pull it through the remaining stitches to close the top.
  • Circular needles work best for the body of the hat; switch to double-pointed needles when the crown gets too tight to fit on the circular needle.

Cast on and join without twisting

Cast on your chosen number of stitches using the long-tail cast-on or your preferred method. For an adult hat, cast on between 80 and 100 stitches depending on head size and yarn weight. Lay the cast-on edge flat on the table and check that the stitches form a circle without a twist. A twist means the cast-on edge spirals around the needle instead of lying flat; if you knit over a twist, you will create a Möbius loop instead of a hat.

Once you are certain there is no twist, join the stitches in a circle by knitting the first stitch with the yarn attached to the last cast-on stitch. Some knitters place a stitch marker on the needle right after the join to mark the beginning of each round. This marker helps you see where one round ends and the next begins.

Knit the body in stockinette stitch

Knit every stitch of every round until the hat measures about 7 to 8 inches from the cast-on edge. This creates stockinette stitch, which looks like a smooth V-pattern on the right side. Because you are working in the round, you knit every round rather than alternating knit and purl rows as you would if knitting flat.

The fabric will naturally curl at the cast-on edge. This is normal and expected. Many knitters add a ribbed cuff (knit 2, purl 2 repeated around) for the first inch to prevent rolling, then switch to stockinette for the body. If you choose to add ribbing, knit the ribbed section first, then switch to stockinette and continue until the hat is ready for the crown.

Decrease stitches to shape the crown

When the hat reaches the desired length, begin decreasing to close the top. A common decrease method is to knit 2 stitches together (K2tog) at evenly spaced intervals around the hat. For example, if you cast on 80 stitches, you might decrease 8 stitches per round by working K2tog every 10 stitches.

On the first decrease round, knit 8 stitches, then knit 2 together. Repeat this pattern around the entire round. On the next round, knit every stitch without decreasing. On the round after that, decrease again at the same intervals. Continue this pattern (decrease round, plain round, decrease round, plain round) until you have 8 to 10 stitches remaining on the needle.

If you are using a circular needle and the crown becomes too tight to fit comfortably, switch to double-pointed needles. Distribute the remaining stitches evenly across three or four needles and continue decreasing with the fourth needle.

Close the top and weave in the yarn end

When 8 to 10 stitches remain, cut the yarn, leaving a 6-inch tail. Thread the tail through a yarn needle and pass it through each remaining stitch on the knitting needle, slipping the stitches off as you go. Pull the yarn tight to gather the stitches and close the hole at the crown.

Weave the yarn end through the inside of the hat for about an inch to find it, then trim any excess. Turn the hat right-side out if you have been working with the wrong side facing you, and try it on. The cast-on edge will still curl slightly; blocking (wetting and pinning the hat to shape) can reduce this, though many knitters leave it as is.

Switch to double-pointed needles when the circular needle becomes too tight

As the crown decreases and fewer stitches remain, a 16-inch circular needle becomes uncomfortable to work with because the stitches bunch up and the needle feels cramped. This is the moment to move to double-pointed needles. Slip your remaining stitches onto three or four double-pointed needles, distributing them evenly so no needle is overloaded.

Continue knitting with the fourth needle, working around the circle just as you did on the circular needle. Double-pointed needles feel different at first — the needle you are working with is shorter and lighter — but the stitch pattern and decrease method stay the same. Many knitters find double-pointed needles easier for the crown because they can see the stitches more clearly and control tension more precisely.

Troubleshooting common problems

If your hat is too loose or too tight, the issue is usually the cast-on number or the needle size. A hat that slides down your head means you cast on too many stitches or used needles that were too large. A hat that feels snug or uncomfortable means you cast on too few stitches or used needles that were too small. Write down the cast-on number and needle size of hats that fit well so you can repeat them.

If you see a gap or hole where you joined the cast-on stitches, pull the yarn gently on the first few stitches to tighten them. This is normal and usually disappears once you have knitted a few rounds. If your hat has a visible jog where the rounds meet (a slight step in the pattern), this is also normal in circular knitting and becomes less noticeable with wear and washing.

Frequently Asked Questions

Can I knit a hat on straight needles instead of circular needles?

Yes, but you will need to knit the hat in two flat pieces and sew them together. This takes longer and creates a visible seam. Circular needles or double-pointed needles are the standard choice for hats because they eliminate the seam and work faster.

What size circular needle do I need for an adult hat?

A 16-inch circular needle is standard for most adult heads. If your head is very large or very small, you may need a 20-inch or 12-inch needle instead. The needle should be short enough that the stitches fit comfortably without bunching, but long enough that you can knit without the needle tips poking you.

How many stitches should I cast on?

This depends on your yarn weight, needle size, and head circumference. A typical adult hat in worsted weight yarn on US 6 to US 8 needles uses 80 to 100 stitches. If you are unsure, cast on 88 stitches and measure the circumference of the tube before you start the crown. It should measure about 18 to 20 inches around.

What happens if I twist the cast-on stitches?

If you knit over a twisted cast-on, you will create a Möbius loop — a single-sided surface — instead of a tube. The hat will not be wearable. Always lay the cast-on edge flat and check for twists before you join and knit the first round.

Do I have to add a ribbed cuff?

No. A ribbed cuff (knit 2, purl 2) helps prevent the cast-on edge from rolling and adds stretch so the hat fits snugly. But stockinette alone works fine if you prefer a simpler pattern. Many knitters add ribbing because it looks finished and fits better, but it is optional.