Simply measure the circumference of your head in inches or centimeters, holding the tape or string snug, but not too tight, just above your ears – which is right about where your hat will sit. The job is made easier if you can recruit the neighbor or a friendly cop to take the measurements for you. If none is available, use a mirror and measure several times to ensure accuracy. Then consult the chart below to determine your equivalent size.
Method B: String
No measuring tape? No problem. Cut a 30″ piece of string. Use the string to measure your head, then measure the length of string used.