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Hat size chart & calculator: knit and crochet beanies

Head sizes from preemie to adult, then the stitches to cast on, hat height and crown shaping for your gauge, or the crown diameter for a crochet hat.

Made by

Size

Style

Stitches

Rows

Measured over

Negative ease (%)

Stitch count multiple

The crown shaping assumes a classic top: decreases worked in equal sections, every other round and then every round.

Hat size chart

Size	Head circumference	Knitted hat around (10% ease)	Beanie height
Preemie	9–12 in 22.9–30.5 cm	8.1–10.8 in 21–27 cm	4.5 in 11.4 cm
Baby	14–16 in 35.6–40.6 cm	12.6–14.4 in 32–37 cm	6 in 15.2 cm
Toddler	16–18 in 40.6–45.7 cm	14.4–16.2 in 37–41 cm	7 in 17.8 cm
Child	18–20 in 45.7–50.8 cm	16.2–18 in 41–46 cm	7.5 in 19.1 cm
Tween	20–22 in 50.8–55.9 cm	18–19.8 in 46–50 cm	8 in 20.3 cm
Adult woman	21–23 in 53.3–58.4 cm	18.9–20.7 in 48–53 cm	8.5 in 21.6 cm
Adult man	22–24 in 55.9–61 cm	19.8–21.6 in 50–55 cm	9 in 22.9 cm

Head circumferences follow the Craft Yarn Council’s sizing standards. Heights are typical for a beanie that covers the ears; add about 2½ in for slouch or a folded cuff.

Measure first

Size charts give ranges, and heads vary more than ages suggest. If you can, measure: run a soft tape around the head across the middle of the forehead and just above the ears, where the brim will sit. For a gift, measure a hat that fits the person well, laid flat and doubled.

How the numbers are worked out

The hat circumference is the head size minus the negative ease. Multiply it by your stitches per inch and round to your stitch multiple, and you have the cast-on. The crown depth comes from the number of decrease rounds and your row gauge, so the calculator tells you exactly when to start the decreases for the height you chose.

For crochet worked from the top down, the crown is a flat circle. Its circumference has to reach the hat circumference, and a circle’s diameter is its circumference divided by π, which is why a 20 inch hat starts with a circle about 6.4 inches across.

Planning a colourwork hat? Chart it on knitting graph paper sized to your gauge, and check needle sizes with the needle converter.

How to use it

Choose a size from preemie to adult, or measure the head around the forehead and above the ears and enter it.
Pick knitting or crochet and the style: beanie, slouchy or with a folded cuff.
Enter your gauge in the stitch you will use for the body of the hat.
Knitters get the cast-on, the height to start the crown and the crown decreases. Crocheters get the width of the flat crown circle and how far to work even.

Questions

What is the average head circumference for a hat?

According to the Craft Yarn Council, adult women typically measure 21–23 inches (53–58.5 cm) and adult men 22–24 inches (56–61 cm). Babies measure about 14–16 inches, toddlers 16–18 and children 18–20.

How much negative ease should a hat have?

Knitted hats are usually made about 10% smaller than the head, around 2 inches for an adult, so they stay on. Stretchy ribbing can take more. Crochet fabric stretches less, so 0–5% is plenty for most crochet hats.

How tall should a beanie be?

An adult beanie that covers the ears is about 8½–9 inches from brim to crown. Add about 2½ inches for a slouchy hat or for a cuff that folds back.

Why should my cast-on be a multiple of 8?

A classic crown is decreased in 8 equal sections, and a multiple of 8 also works for 1×1 and 2×2 rib. Choose another multiple if your stitch pattern needs it.

How do I size a top-down crochet hat?

Crochet a flat circle until its diameter equals the hat circumference divided by π (about 3.14), then stop increasing and work even until the hat is tall enough.