Approximate size guide:
BLACK
Small - 6 3/4 to 6 7/8
Medium - 7 1/8
Large - 7 1/4 (nothing works for 7 3/8)
X Large - 7 1/2 to 7 5/8
BONE
Small - 6 3/4 to 6 7/8
Medium - 7 to 7 1/8
Large - 7 1/4 to 7 3/8
X Large - 7 1/2 to 7 5/8
CORDOVA
Small -
Medium - 7 to 7 1/8
Large - 7 1/4 (nothing works for 7 3/8)
XLARGE - 7 1/2 to 7 5/8
The closer you are to the upper limit the better the fit.
Foam reducing tape is sent with each hat to adjust as needed.