Measurements for Designers: Hat Sizes

I love crochet hats. I love crochet everything, obviously, but hats are especially nice because they make a convenient handmade gift. They are quick to make, do not require a lot of materials, and work as a gift for both the males and females (and children!) in your life.

Jayne Cobb Hat
The Jayne Cobb hat is a fine example of a unisex hat for all ages.

An added bonus: you don't really need a pattern to make a hat. Just crochet a circle roughly the same circumference as the giftee's head, then crochet evenly until the hat is as long as you'd like it to be.

But what if you don't know the recipient's head size and you want to surprise them? What if the recipient hasn't been born yet? My friends, I have some measurements for you. These are general guidelines, of course; not every human fits in a standardized box. But these measurements will give you a rough idea of how big to make your hats in various sizes.

Hat Measurements in Inches
Measurement Preemie Newborn 0-6m 6-12m Toddler Child Teen Woman Man
Circumference 12 14 16 17 19 20.5  21 21 22
(crown to brow)
3 3.5 4 4.25 4.75 5 5.25 5.25 5.5

For a brim that folds up, add an extra inch or two (or three!) to the length.