I made this Jester Hat for my little nephew Quinn's first birthday. His mighty Irish noggin was too big, and the hat didn't fit. I am listing it on etsy; it's too nice to let it sit on the shelf. This was an great pattern and makes up quickly, so I have time to knit another one for him before it gets cold here.
For this hat, I used two wool yarns: the gray is Brown Sheep Lamb's Pride Superwash in charcoal heather, and the purple is Lion Brand Wool-Ease in grey ragg. Both can go right into the washing machine. The pattern was a free Ravelry download, Jester Hat, by Elizabeth Morrison.
The yarns are aran weight and I cast on 72 stitches. This gave me a hat that measured 6 inches across the ribbing when measured flat, and 7 inches across the body, with a total height of 6.5 inches. Quinn's head measures 19 inches around. If I need to add 6 more inches of ribbing, then I think I need to add another 36 cast on, for a total of 108 stitches.