This pattern (all sizes) is available free on my website, or you can purchase an ad-free printable PDF here. The pattern is written for the following sizes:

Adult large: 23”
Adult small: 21”
Child: 19”
Toddler:17”

You will need 140-180 yards of DK weight yarn and a size G crochet hook. You may also need a size H crochet hook if you find your slip stitch rows too tight to comfortably work into. The hat is worked top down and requires only half double crochet, slip stitch through the back loop only, and chain stitches!

The sample pictured is an adult large hat modeled on an adult large head (my own) and a child (where it is a little big for her). The hat has negative ease and should stretch on for a comfortable fit.