Use whatever yarn craft you prefer (this one was done with the Addi Express Kingsize knitting machine) and use these measurements as a guide for an adult size hat. Basically, it’s a tube, both ends gathered closed with one end stuffed inside another!
Some may find this tutorial interesting as I discuss the way yarn size/type affects sizing. I am not a knitter but my knitter friends tell me that the Addi Express Kingsize = 5.5mm needles. There are 46 needles on the machine and using Deborah Norville Everyday Soft Worsted it made a tube about 15 inches in circumference. Crocheters, measure a hat you know fits well and using the same type yarn and hook size, make your tube the same circumference as the bottom of your existing hat! Loomers will know just what loom to use to achieve the size they want!!