The chart below will give you a close approximation of the correct cap/hat size to order.

Using a tape measure (in inches); Measure the circumference of the head where the cap/hat is normally worn to find the length in the 1st column below. The tape measurement corresponds to the size.

HEAD MEASUREMENT Inches U. S. HEAD SIZE CAP/HAT SIZES
22 1/8 TO 22 1/2 6 7/8 TO 7 Small
22 7/8 T0 231/4 7 1/8 T0 7 1/4 Medium
23 5/8 T0 24 7 3/8 T0 71/2 Large
24 3/8 TO 24 3/4 7 5/8 TO 7 3/4 X-Large
25 1/8 TO 25 1/2
7 7/8 TO 8 XX-Large