Baby Hat Knitting Patterns: Newborn to 24 Months

October 9, 2026 / Marie

In Brief

To knit a baby hat in the round, 40 cm (16“) circular needles eliminate the need for sewing; for a flat, one-piece hat, you only need a simple back seam and a cinched top.
Head circumference varies from 32-36 cm at birth to about 48-50 cm by 24 months: this measurement, rather than age alone, should guide your stitch count.
A newborn hat is knitted without complex decreases: use ribbing, garter stitch, or stockinette, then simply cinch the top with a yarn tail.
To knit a baby hat for 12 to 24 months, the crown is closed using regular decreases spaced every 3 rows over a height of 4 to 6 cm.
Your choice of stitch (garter, stockinette, 2x2 rib) affects the elasticity and comfort around the ears, which is a sensitive area for infants.

Want to knit a baby hat but can’t decide between straight and circular needles, or aren’t sure where to place the decreases so the crown fits perfectly? This guide details both methods—in the round and flat in one piece—including measurements by age (newborn, 0-3, 3-12, 12-24 months) and the exact placement of crown decreases. With this pattern in hand, you’ll know which version to choose based on your tools and skill level, and how to achieve a hat that stays put without being too tight or too loose.

Baby Hat In the Round or Flat: Which Method to Choose?

Both techniques produce the same visual result but differ in execution.

Knitting in the round, using short circular needles (40 cm/16“) or double-pointed needles (DPNs), avoids all sewing: the cast-on stitches immediately form a closed tube, and the hat is finished by cinching the crown with yarn. This is the fastest method for a clean professional finish, but it requires knowing how to join the cast-on row without twisting it—a twist at this stage results in a spiral hat that cannot be fixed without frogging the whole project.

Knitting flat in one piece, using classic straight needles, produces a rectangle that is later closed with a vertical back seam and a cinched top. This is the most accessible choice for beginners who don’t yet own circular needles or who prefer to easily identify the right and wrong sides without monitoring a join row. The only requirement is an invisible seam, using the mattress stitch, to avoid an uncomfortable lump at the back of the head.

In practice, knitting flat works well for garter stitch models (like the newborn hat below), as this stitch doesn’t curl and hides a discreet seam well. Knitting in the round is preferable whenever stockinette stitch is used, as it tends to curl at the edges and benefits from a continuous structure.

Sizes and Head Circumference: What to Measure Before Casting On

The most common mistake isn’t the stitch or the method, but the number of stitches cast on at the start, often calculated by age rather than actual measurement. A 12-month-old baby doesn’t always have the same head size as another baby of the same age.

Standard guidelines (to be verified with a flexible measuring tape if possible):

Newborn to 1 month: 32 to 36 cm circumference.
3 months: approximately 40 cm.
6 to 12 months: 43 to 46 cm.
12 to 24 months: 46 to 50 cm.

(source: hats knitted in the round, Accrochez vos Aiguilles)

A knitted hat stretches slightly with wear: aiming for a final measurement equal to 90-95% of the actual head circumference provides a secure fit without leaving marks on the forehead. To knit a baby hat for 12 to 24 months, aim for a circumference of about 44 to 47 cm once the knitting is finished and lightly relaxed during blocking.

The number of stitches to cast on then depends on your gauge (the number of stitches per 10 cm with your chosen yarn and needles). A common example using “baby weight” yarn (3.5 to 4 mm needles, approx. 22 stitches per 10 cm in stockinette): cast on 92 to 100 stitches for a 12-24 month hat, compared to 76 to 84 stitches for a newborn hat.

Knitting a Newborn Hat: The Simplest Pattern

The newborn hat is the best starting point for beginners because it requires no complex decreases.

Materials: 3.5 mm straight or circular needles, baby weight yarn (about 50g is enough), a darning needle for finishing.

Steps:

Cast on 76 to 84 stitches depending on your gauge and the target head circumference (32-36 cm).
Knit 4 to 5 cm in 1x1 or 2x2 ribbing for a flexible edge that won’t tighten against the forehead.
Continue in garter stitch (knit every stitch on every row) or stockinette, depending on the desired texture, until the total height reaches 12 to 14 cm from the cast-on edge.
Without intermediate decreases, cut the yarn leaving a tail of about 30 cm. Thread it through a darning needle, pass it through all remaining stitches on the needle, remove the knitting needle, and pull tight to close the top.
If the hat was knitted flat, sew the back seam using the mattress stitch from the bottom edge to the top.
Weave in the ends on the inside of the hat.

Garter stitch is particularly recommended for this model: it doesn’t curl at the edges, eliminating the need for a hem or separate border, and its regular texture is soft against a newborn’s skin.

Knitting a Baby Hat In the Round: 12-24 Month Pattern with Crown Decreases

For an older baby, the crown must be shaped with decreases to fit the rounded shape of the skull without excess fabric.

Materials: 40 cm (16“) 4 mm circular needles (or DPNs if preferred), baby weight or sport weight yarn, a stitch marker to mark the beginning of the round.

Steps:

Cast on 92 to 100 stitches (adjust based on your gauge to aim for 44-47 cm circumference). Join in the round, ensuring the stitches are not twisted, and place a marker at the join.
Knit 4 to 5 cm in 2x2 ribbing for an elastic edge that stays in place over the ears.
Continue in stockinette (knit all stitches, since you are working in the round) until the height is 10 to 12 cm from the cast-on edge.
Begin crown decreases: on the first decrease round, knit 2 together (k2tog) every 8 to 10 stitches, evenly distributed around the circle. Knit the next 3 rounds without decreases.
Repeat the same decrease pattern 3 rounds later, slightly narrowing the interval between decreases each time (for example: 7, then 6, then 5 stitches between each k2tog), until the crown measures about 4 to 6 cm in height from the start of the decreases.
(progressive decrease method, 3 petites mailles). When 8 to 12 stitches remain, cut the yarn leaving a 20 cm tail, pass it through the remaining stitches, and pull tight.
Weave in the ends and add a pom-pom if desired by attaching it directly to the closing point at the top.

Spacing the decreases over several rounds rather than in one go avoids a sharp “star” effect at the top and creates a rounded crown that closer resembles the natural shape of the head.

Knitting a Baby Hat in One Piece: Flat Version with Decreases

If you only have straight needles, the same result is achieved by knitting flat, with one additional seam.

Cast on the same number of stitches as for the circular version (92-100 for 12-24 months), but remember to add a stitch for the seam on each side (add 2 stitches total).
Knit the ribbing and then the body of the hat in classic stockinette (one row knit, one row purl), working on the right side of the fabric.
For the crown, distribute the decreases in the same way as the circular version, but only on the knit rows (purl rows are worked as they appear).
Once 8 to 12 stitches remain, bind them all off together or cinch them with yarn as in the circular version.
Fold and sew the back seam using the mattress stitch, from bottom to top, including the top if the stitches were bound off rather than cinched.

This one-piece flat version is the easiest to correct if you make a mistake: unlike knitting in the round, you can see the entire row flat and quickly spot a dropped stitch or a misplaced decrease.

Choosing Your Yarn and Needles for a Baby Hat

Yarn choice primarily affects the final comfort: prioritize a soft, non-irritating yarn suitable for a baby’s sensitive skin, and check the label for the manufacturer’s recommended needle size (usually 3.5 to 4 mm for classic baby weight yarn). Criteria for selection, washing, and hypoallergenic materials are covered in detail in our dedicated article Baby Yarn: Knitting Guide; this guide focuses specifically on the hat pattern and technique.

As for needles, a 40 cm (16“) circular is suitable for most baby head sizes without the stitches stretching too much between the tips. For very small newborn head sizes (under 34 cm), some knitters prefer the “magic loop” method with a longer circular needle rather than DPNs, which can be trickier to handle with such a small number of stitches.

Finishing: Pom-poms, Edges, and Blocking

A well-finished baby hat depends as much on the finishing touches as the pattern itself. For a pom-pom, two cardboard circles (about 6 cm diameter for a 12-24 month hat, 4-5 cm for a newborn hat) eliminate the need for a dedicated tool: wrap the yarn around the two overlapping circles, cut around the edges, tie firmly between the two circles before removing them, and trim with scissors. Attach it directly to the closing point at the top.

If the hat gaps slightly once finished, an I-cord (a tubular knit of 3-4 stitches, several dozen centimeters long) threaded through the ribbing at ear level allows you to tighten the fit without re-knitting. Finally, gentle blocking—lightly moistening the hat and letting it dry flat on a towel without hanging it to avoid stretching—evens out the stitch tension and provides a more professional look than straight off the needles.

Common Mistakes to Avoid

Casting on without checking the gauge: two yarns of the same apparent thickness can yield different gauges depending on their twist, throwing off all size calculations.
Knitting ribbing too loosely: a hat brim that isn’t tight enough will end up sliding over the baby’s eyes after a few months of growth.
Twisting the cast-on row in the round: this error can only be fixed by frogging the work; ensure all stitches are facing the inside of the circle before joining.
Spacing crown decreases irregularly: this creates visible pleats at the top rather than a smooth curve.
Forgetting the final blocking: a light wash and flat dry relaxes the stitches and reveals the true size of the hat, which can sometimes differ from the measurement taken while still on the needles.

FAQ

What is the head circumference for a 12-24 month baby hat?

Expect an actual head circumference between 46 and 50 cm depending on the child, but aim for a finished hat around 44 to 47 cm, as the knit stretches slightly during use and needs to stay in place.

Do I need circular needles to knit a baby hat in the round?

Short circular needles, around 40 cm (16“), work for most baby sizes. For very small newborn sizes, the magic loop method with a longer circular is often easier to handle than DPNs.

How do I knit a baby hat in one piece without messing up the seam?

Knit the hat flat in stockinette, then sew the back seam using the mattress stitch from bottom to top, stitch-to-stitch, for an invisible seam on the right side. Sew with the knitting lying flat in front of you to align the rows perfectly.

At what height should I start the crown decreases?

Generally between 10 and 12 cm from the cast-on edge for a 12-24 month hat. For a newborn hat, no decreases are necessary; it is closed directly with yarn once the total height is reached.

Which stitch should I choose for a newborn hat: garter or stockinette?

Garter stitch is often recommended for a first hat because it doesn’t curl at the edges and requires no additional border. Stockinette looks sleeker but curls slightly at the sides, which may require a wider ribbed border.

How many stitches should I cast on for a baby hat based on age?

It depends on your gauge, but as a guide using classic baby weight yarn (3.5-4 mm needles), cast on 76 to 84 stitches for a newborn hat and 92 to 100 stitches for a 12-24 month hat.

Can I knit a baby hat if I don’t know how to decrease?

Yes, for a newborn hat: the closure is simply done by cinching all remaining stitches with yarn, without any intermediate decreases. Decreases only become necessary for larger sizes where the crown must be shaped over several centimeters.

How do I stop the baby hat from slipping or being too tight?

Always knit a ribbed border (1x1 or 2x2) of 4 to 5 cm before the body of the hat: the elasticity of the ribbing keeps the hat in place without marking the forehead, unlike a stockinette or garter edge which remains flat and less secure.

Going Further

Whether you choose the circular version or the flat one-piece version, the logic remains the same: an elastic border, a straight body, and then a crown shaped by progressive decreases. Once you’ve finished your first hat, you can apply the same method to other sizes simply by adjusting the cast-on number based on the child’s actual head circumference. If you are looking for suitable baby yarn or short circular needles to get started, our baby knitting selection gathers all the materials needed for this type of pattern.