What you need before you start
A basic hat on round needles requires four things: a set of circular needles or double-pointed needles in the size your yarn calls for, yarn (usually 200 to 400 yards depending on hat size), a yarn needle to weave in ends, and a pattern. Most patterns tell you the needle size and yardage upfront. If you are working without a pattern, circular needles between US 4 and US 8 work for most worsted-weight yarn.
The needles themselves matter more than you might think. Circular needles have two needle tips connected by a cable; double-pointed needles (DPNs) are short needles with points on both ends, sold in sets of four or five. Circular needles are easier to hold and less likely to drop stitches, so they are the better choice if you have never knit in the round before. The cable length should be 16 inches or shorter for a hat — a cable that is too long makes the stitches spread out and become hard to work.
Cast on between 80 and 120 stitches, depending on head size and yarn weight. A child's hat typically needs 80 to 100 stitches; an adult hat needs 100 to 120. If you are unsure, cast on the lower number — a slightly loose hat is easier to fix than one that is too tight.
Key Takeaways
- Cast on 80 to 120 stitches on circular needles, join them in a circle without twisting, and knit in rounds using stockinette stitch (knit every round) until the hat reaches your desired length.
- Decrease stitches evenly around the crown by knitting two stitches together at regular intervals, reducing by about 10 percent of your total stitches every few rounds until only 8 to 10 stitches remain.
- Cut the yarn, thread it through the remaining stitches with a yarn needle, pull tight to close the crown, and weave in the loose ends on the inside of the hat.
- Ribbed cuffs (alternating knit and purl stitches) at the bottom help a hat stay on your head and are worked the same way as the body, just with a different stitch pattern.
- Mistakes in the first few rounds are visible from the inside only, so do not rip back unless the error affects how the hat fits.
Joining your stitches without a twist
After you cast on, your stitches sit in a line on the needle. Before you knit the first round, you must join them into a circle. This is the most common mistake beginners make, and it ruins the hat if you do not catch it: if your cast-on row twists around the needle, your finished hat will have a spiral seam running through it.
To join without twisting, lay the needle flat on a table after casting on. Look at the cast-on edge — it should form a straight line around the needle, not spiral. If it spirals, pull the needle out and recast on. Once the cast-on is straight, hold the needle so the working yarn hangs from the right needle tip. Knit the first stitch of the round, pulling the yarn snug so the cast-on edge closes into a circle. You are now knitting in the round.
From this point forward, you will always knit in the same direction around the circle. The stitches move from the left needle tip to the right, then you switch hands and the right needle becomes the left. This feels strange at first — your hands move in a different pattern than flat knitting — but after a few rounds it becomes automatic.
Knitting the body in stockinette stitch
The simplest hat is made entirely in stockinette stitch, which means you knit every stitch of every round. This creates the smooth, V-patterned fabric you see on most hats. Knit for 6 to 8 inches, depending on how long you want the hat to be before the crown shaping begins. Measure from the cast-on edge up the side of the hat as you work.
As you knit, you may notice that the first stitch of each round looks loose or sloppy. This is normal and happens because you are moving the yarn from the back needle to the front needle at the start of each round. The tension evens out after a few rounds, and any looseness disappears when you weave in the ends. Do not try to fix it by pulling the yarn tighter — that will make the stitch even worse.
If you want a ribbed cuff instead of a plain edge, work the first 1 to 2 inches in ribbing before switching to stockinette. Ribbing means alternating knit and purl stitches — for example, knit 1, purl 1 all the way around. This creates vertical lines that stretch and grip, which is why ribbed cuffs keep hats from sliding off. After you finish the ribbed section, switch to stockinette and continue until you are ready to shape the crown.
Shaping the crown with decreases
Once the hat body reaches the length you want, you begin decreasing — reducing the number of stitches so the fabric narrows into a point at the top. The most common decrease for hats is knit 2 together (k2tog), which means inserting your needle through two stitches at once and knitting them as one. This removes one stitch per decrease.
Plan your decreases in rounds. If you cast on 100 stitches, a straightforward decrease round looks like this: knit 8 stitches, knit 2 together, knit 8 stitches, knit 2 together — repeat this pattern all the way around. This removes 10 stitches in one round, leaving you with 90. After a few plain rounds, do another decrease round, spacing the decreases the same way. Each decrease round removes about 10 percent of your stitches.
Continue decreasing every few rounds until you have only 8 to 10 stitches left on the needle. The last few rounds become difficult to work because the stitches are crowded — this is when you may switch to double-pointed needles if you are using a circular needle, because DPNs handle small numbers of stitches more easily. If you stay with the circular needle, work slowly and carefully.
Closing the crown and finishing
When only 8 to 10 stitches remain, cut the yarn, leaving a 6-inch tail. Thread the tail through a yarn needle (the blunt needle with a large eye). Insert the yarn needle through each remaining stitch on the knitting needle, sliding them off as you go. Pull the yarn tight — this closes the crown into a point. Tie a knot on the inside of the hat to find it.
Weave the loose ends into the fabric using the yarn needle. On the inside of the hat, run the needle through several stitches in one direction, then back in the opposite direction, creating a small zigzag. This anchors the yarn so it does not unravel. Trim any remaining tail close to the fabric. Repeat with the cast-on tail at the bottom of the hat.
Turn the hat right-side out and try it on. If the crown closing left a small hole, that is normal and closes up when the hat is worn. If the hat is too tight, you can gently stretch it and let it dry flat. If it is too loose, you can felt it slightly by washing it in warm water and laying it flat to dry, which shrinks the fabric a little.
Common mistakes and how to fix them
The most common error is twisting the cast-on, which creates a spiral seam. If you notice this after knitting a few rounds, rip back to the cast-on and rejoin without the twist. If you notice it after you have knitted several inches, you can either rip back or accept the seam — it is visible from the inside only and does not affect how the hat fits.
Loose stitches at the beginning of each round are normal and do not need fixing. Dropped stitches (stitches that slip off the needle) are more serious. If you drop a stitch, pick it up with a crochet hook before it unravels more than one row down. Insert the hook through the dropped stitch from front to back, hook the horizontal strand of yarn above it, and pull the strand through the stitch. Repeat for each row the stitch dropped.
Uneven tension — some stitches tight, some loose — usually improves as you knit more hats. If one section is noticeably tighter than the rest, it is often because you were holding the yarn differently in that section. This evens out over time and is not worth ripping back to fix.
Yarn weight and needle size combinations
| Yarn Weight | Needle Size (US) | Yardage for Adult Hat | Cast-On Stitches |
|---|---|---|---|
| Fingering (thin) | 1 to 3 | 400 to 500 | 100 to 120 |
| Sport (light) | 3 to 5 | 300 to 400 | 100 to 120 |
| Worsted (medium) | 6 to 8 | 200 to 300 | 100 to 120 |
| Bulky (thick) | 9 to 11 | 150 to 200 | 80 to 100 |
Frequently Asked Questions
What is the difference between circular needles and double-pointed needles for hats?
Circular needles have two tips connected by a cable and are easier to hold for beginners. Double-pointed needles are four or five short needles with points on both ends and work well once you are comfortable with the technique. Most people start with circular needles and switch to DPNs only for the final crown shaping when stitches are too few for the circular cable.
How do I know if my hat will fit?
Measure the head of the person who will wear the hat around the fullest part (usually just above the ears). A hat should be about 1 to 2 inches smaller than this measurement when laid flat, because the ribbing and fabric stretch. If you cast on 100 stitches on US 6 needles with worsted yarn, the hat will be roughly 18 inches around — suitable for most adults.
Can I knit a hat with straight needles instead of round needles?
Yes, but you will have a seam running up the back of the hat. Knit flat (back and forth) until the hat reaches the desired length, then bind off. Sew the two edges together with a yarn needle using a mattress stitch. Most people prefer round needles because they eliminate the seam, but a seamed hat works just as well.
What should I do if I run out of yarn before the hat is finished?
If you run out during the body, you can bind off early and make a shorter hat, or you can add a contrasting color yarn to finish. If you run out during the crown shaping, bind off the remaining stitches and close the crown with a drawstring instead of pulling the yarn tight. A drawstring hat is less polished but still functional.
How tight should I pull the yarn when I close the crown?
Pull it snug enough that the hole closes completely, but not so tight that you distort the stitches around the crown. The yarn should feel firm but not strained. If you pull too hard, you may break the yarn or create a puckered point instead of a smooth one.