Head circumference and finished hat sizing from newborn to adult XL.
| Size | Age | Head circumference (cm) | Hat height (cm) |
|---|---|---|---|
| Preemie | Premature | 28 – 33 | 13 – 15 |
| Newborn | 0 – 3 months | 34 – 38 | 15 – 17 |
| Infant | 3 – 6 months | 40 – 43 | 17 – 18 |
| Toddler | 1 – 3 years | 44 – 48 | 18 – 19 |
| Child | 4 – 10 years | 50 – 52 | 19 – 20 |
| Teen / Adult Small | Adult (S) | 52 – 54 | 20 – 21 |
| Adult Medium | Adult (M) | 55 – 57 | 21 – 22 |
| Adult Large | Adult (L) | 58 – 60 | 22 – 23 |
| Adult XL | Adult (XL) | 61 – 63 | 23 – 24 |
Crochet fabric has some stretch — most patterns are worked 2.5–5cm smaller than the head measurement for a snug fit.
Hat sizing comes down to two numbers: head circumference (how far around the hat needs to stretch) and hat height (how tall the crown needs to be, including any brim). Because crochet fabric has natural stretch, most patterns are written with a small amount of negative ease, meaning the finished hat measures a little smaller than the wearer's actual head circumference for a secure, snug fit.
How do I measure head circumference for a crochet hat?
Wrap a soft tape measure around the head just above the eyebrows and ears, at the widest point, and use that measurement to find the closest size on the chart.
Should a crochet hat be smaller than head circumference?
Yes — most crochet hats are worked about 5-10% smaller than the actual head measurement (negative ease) since the fabric stretches to fit snugly.
How tall should a beanie be?
A standard beanie is typically 18-23cm tall depending on size and whether it has a fold-up brim; slouchy styles run several centimeters taller.