Answer by
equiscero (20)

U.S. hat sizes measure head diameter in inches, European sizes measure head circumference in centimeters. To convert U.S. to German sizes multiply your American size in inches by 7.98 and round it to the closest full number. Example: U.S. size is 6 3/4, then 6.75*7.98=53.87 so German size is 54.