How to size
UFO
SIZE INCHES CM HAT SIZE
X-SMALL 20 7/8 - 21 1/4 53-54 6 5/8 - 6 3/4
SMALL 21 5/8 - 22 55-56 6 7/8 - 7
MEDIUM 22 3/8 - 22 3/4 57-58 7 1/8 - 7 1/4
LARGE 23 1/8 - 23 1/2 59-60 7 3/8 - 7 1/2
X-LARGE 24 - 24 3/8 61-62 7 5/8 - 7 3/4
XX-LARGE 24 3/4 63 7 7/8