AKA_ The knit bunny ran down the rabbit hole... For pattern Hat Formula: Determine gauge and desired hat size (1-2" smaller than the head). Decide number of repeats (11 * 7, 8, 9, 10... ) based on the total stitch count needed. Note that some rows have 2 decreases and the stitch count changes. Work a 3/3 ribbed hem. Start with a circle cast on.
Shown with a cast-on count of 2 stitches.