To figure out what size fitted hat to get, you must first measure your head. You can use a tape measure (or a length of string that you will have to hold up to a tape measure) to determine the length. Place the string or tape around your head about 1/8" above your ear, across the mid-forehead, completely circling your head. Hold the tape firmly, but not too tightly. Basically you need to measure your head exactly where the hat will sit. If your measurement falls between sizes, choose the next largest size.
Another valid method to determine fitted hat size is to try on a fitted to see if it fits and check the size. If you don't own a hat, then try on a random hat next time you are visiting a shop that stocks fitteds such as Lids. Sizes, even though they do vary depending on the manufacturer, are technically universal.
You may also be interested in using our interactive fitted hat sizer. This tool can be found on every fitted hat product page. Once you've measured your head, enter that number (in inches) and the tool will tell you what fitted hat size is ideal for you.
Please understand that hats are not unlike other apparel, in that sizes can vary somewhat from one manufacturer to another. We cannot guarantee that by following these instructions any assurance of a perfect fit.