I beleive it's the distance of your head from front to back in inches. If thats true though then that would mean this hat is actually a size 8. Because from front to back the hat measures 8" rather than 7 1/2". I really hope this helmet fits.How exactly does one measure your head size, around the forehead and such or how?
Well, mine is a large melon. Without the keyslots cut out, I have to cock it to the side about a quarter turn and kinda slip it on. Snug is the word of the day.I wear a 7 3/8. My nose is pressed against the visor when I put my MS Mystery on. I must have one of those Alien heads.