Measure the head
Wrap a soft tape measure around the widest part of the head: across the forehead just above the eyebrows, above the ears, and around the back. Keep the tape snug but not tight, and read the number in centimetres.
No tape measure? Use a piece of yarn, mark where it meets, then lay it flat next to a ruler.
Typical hat sizes
- Newborn: about 36 cm head
- Baby, 3–12 months: 43–46 cm
- Toddler: about 48 cm
- Child: about 51 cm
- Teen: about 53 cm
- Adult: 57 cm (small) to 61 cm (large)
These are typical ranges, not rules. If you can measure the real head, use that number.
Make the hat a little smaller
Crochet and knit fabric stretches, so a hat is made 2–5 cm smaller than the head. That gap is called negative ease. A beanie that sits close needs more of it, a slouchy hat needs less.
Let Crochet to Size do the maths
Every hat design on Crochet to Size asks for the size or the head measurement and your yarn, then writes the pattern with every round counted. Pick a size and the crown, body and brim are worked out for you.
