Did I read on here somewhere that to figure the size hat to make is to simply measure your head (where the brim would sit) and then subtract 5 inches?
If I have it figured correctly, my head is about 23 inches, so subtracting 5 inches leaves 18 inches. Then if I'm using yarn that is 18 stiches to 4 inches, then I would need to cast on 81 stiches?
And lastly, does needle size matter? The yarn is 18 stiches to 4 inches on sz 8, but if I use size 13, is that huge difference?