Brett H There is no real sizing information for most hoods, generally you would go with the size you use when you rent etc. Average for a man is size large and woman is size med.

Brett H Unfortunately Cressi has not provided us with any hood sizing. Generally for a guy with an average head you go for a Large, if slightly smaller than average you would get a Med and if you are slightly larger than average an XL would be the best choice. Of course if the fit isn't right we always have our PFF program: http://www.leisurepro.com/Popup/Content.aspx?Topic=PFF