The uber-smart Cosy has the answer to the eternal question: When IS the hat DONE?
It’s in her 2nd post in a super helpful series on knitting hats.
approximate hat heights
0-6 mo. – 5 in. (12.7 cm)
6-18 mo. – 6.25 in. (15.9 cm)
18 mo.-4 yr. – 7.25 in. (18.4 cm)
4 yr.-adult s – 8.25 in. (21 cm)
adult m-l – 9 in. (22.9 cm)
Read her whole post here.

Hi! I'm Tara and I'm the Blonde Chicken behind all this yarn! You can read more about how I got this