Guessing at hat sizes is the fastest way to end up with a beanie that perches on top of someone’s head or slides down over their eyes. This hat size chart gives you the head circumference, crown diameter and hat height for every size from preemie to adult large, in inches and centimetres, so your next knit or crochet beanie fits the first time.

Save this page (or pin it) and keep it open the next time you cast on. It works for any beanie pattern, worked top down or bottom up.

In this guide: Full hat size chart · How to measure a head · Baby hat sizes · Kid, teen and adult sizes · Negative ease · How many stitches to cast on · Sizing by hat style · FAQ

Hat Size Chart: Standard Beanie Sizes at a Glance

Hat size charts vary a little from source to source, so treat these as reliable starting points. Every size in this hat size chart is the head measurement, not the finished hat. Your finished hat should be 1 to 2 inches (2.5 to 5 cm) smaller around than the head. More on that below. For an industry reference, the head sizes line up closely with the Craft Yarn Council head circumference chart.

How to Measure a Head for a Hat

All you need is a soft, flexible tape measure.

1. Wrap the tape around the widest part of the head: across the middle of the forehead, just above the ears, and around the fullest part of the back of the head.
2. Keep the tape snug but not tight. It should lie flat without pressing into the skin.
3. Read the number where the tape overlaps. That is the head circumference.
4. Find the closest size in the chart. If the measurement falls between two sizes, choose the smaller one.

Making a surprise gift and can’t measure? Use the age in the chart. For babies, size up one if you aren’t sure, because they grow quickly.

How to Read the Hat Size Chart

Head circumference

Your tape measurement from above. This is the number you match to the chart.

Crown diameter

The distance straight across the flat circle at the top of the hat. If your pattern starts at the crown and works down (very common for crochet beanies), keep increasing until your circle reaches this diameter.

Hat height

The finished length from the brim edge to the top of the crown. For a top down hat, measure from the centre of the crown. For a bottom up hat, measure from the cast on edge.

Baby Hat Size Chart (Preemie to 24 Months)

Baby hats are the most common gift make. If you are knitting or crocheting for a baby shower, the 3 to 6 month or 6 to 12 month size gives the new parents a hat that will still fit when the weather turns.

Kid, Teen and Adult Hat Size Chart

Most adults fall between 21 and 23 inches. A 22 inch head is a good default when you are making a gift for an adult and can’t measure.

The Trick: Make the Hat Smaller Than the Head

Knit and crochet fabric stretches. A beanie that measures exactly the same as the head will feel loose after a few wears and slide off. That built in difference is called negative ease.

Make your hat 1 to 2 inches (2.5 to 5 cm) smaller around than the head. For example, a 22 inch head needs a hat that measures 20 to 21 inches around.

• Ribbed brims and stretchy stitches can take the full 2 inches.
• Dense, less stretchy stitches (like many crochet textures and cables) do better closer to 1 inch.
• For a slouchy beanie, keep the brim snug and add the slouch to the height, not the circumference.

Folded Brim? Add the Fold

The chart height is the height of the finished hat. If your brim folds up, work extra length equal to the fold depth before you finish the crown.

Example: an adult medium hat is 8.75 inches tall. With a 2.5 inch folded brim, work 8.75 + 2.5 = 11.25 inches before folding.

How Many Stitches to Cast On for a Beanie

The hat size chart tells you how big the hat should be. Your gauge tells you how many stitches it takes to get there. This works for any yarn and any pattern, knit or crochet.

For a bottom up knit beanie

1. Find the head size in the chart. Example: adult medium, 22 inches.
2. Subtract the negative ease. 22 − 1.5 = 20.5 inches finished.
3. Knit a gauge swatch in your hat stitch and count the stitches per inch. Example: 18 stitches over 4 inches is 4.5 stitches per inch.
4. Multiply. 4.5 × 20.5 = 92.25, so about 92 stitches.
5. Round to your stitch repeat. A 2×2 rib needs a multiple of 4, and 92 already works. Cast on 92.

For a top down crochet beanie

Work your crown increases until the flat circle matches the crown diameter in the chart (7 to 7.5 inches for adult medium). Then stop increasing and work even rounds until the hat reaches the hat height. If the circle starts to ruffle or cup before it reaches the diameter, your increases are off, so check your stitch count against the pattern.

Tip: to check a hat in progress, lay it flat without stretching, measure straight across and double that number. That is the circumference.

Using the Hat Size Chart for Different Hat Styles

• Fitted beanie: use the chart exactly as written. This is the classic everyday hat.
• Slouchy beanie: keep the circumference from the chart and add 1.5 to 3 inches to the height. The extra length is what creates the slouch.
• Folded brim beanie: add the depth of the fold to the height, as shown above.
• Pom pom beanie: no change. The chart height is for the hat itself, so the pom pom sits on top.
• Cabled or textured beanie: cables and dense crochet stitches pull in and stretch less, so aim for about 1 inch of negative ease and always swatch in the actual stitch.

5 Common Hat Sizing Mistakes

1. Making the hat the same size as the head. Without negative ease, the beanie grows with wear and slides off.
2. Skipping the gauge swatch. Even half a stitch per inch changes an adult hat by about 10 stitches.
3. Measuring the hat while it is stretched. Lay it flat and relaxed before you measure.
4. Starting the crown too late. Begin your decreases when the hat is about 2 inches shorter than the chart height, or the top will come out pointy and tall.
5. Using a firm stitch for the brim. Ribbing (knit) or front and back post ribbing (crochet) gives the brim the stretch it needs to hug the head.

What You Need to Make a Beanie

• Lion Brand yarn: worsted and bulky weights are the easiest to work with for beanies.
• Red Heart Super Saver: an affordable worsted weight that holds up to everyday wear.
• 5.5 mm crochet hook: a common size for worsted weight beanies. Always use the hook size in your pattern.
• Tapestry needle for weaving in ends.
• Soft tape measure for measuring the head and checking your hat as you go.

Free Knit and Crochet Beanie Patterns to Try

• Free Crochet Cable Beanie Pattern (Braided Cables, Fold-Up Cuff)
• Seed Stitch Knit Beanie: Free 2-Hour Beginner Knit
• The Easiest Crochet Hat Pattern
• Two Toned Crochet Beanie
• Hudson’s First Baby Beanie
• Ombre Pony Beanie with a Messy Bun Opening
• Chunky Cable Knit Beanie with a Folded Brim

Making a blanket to match? See my standard blanket sizes guide.

Hat Size Chart FAQ

Save This Hat Size Chart

Pin this chart or bookmark this page so it is ready for your next beanie. And send it to a friend who is about to start a hat. 🧶