I have 13 total small doll hats. 4 of the hats have brimmed edges and 9 hats are just like a pull over hat.
I did try these on a Barbie doll, but they did not fit too well. The brimmed hats did not fit at all, they were too small. The other hats would fit better but still were tight.
The brimmed hats measure 2 1/2" wide and the inside head part measures about 3/4" wide.
The pull over hats are 2 different sizes: 1 3/4" and 2" across bottom edge