Start with a measuring tape (or a piece of string you can measure later), and wrap it around your head, placing it where your hat will sit- typically, at the middle of your forehead and about 1/8" above your ear. Hold the tape firmly, but not uncomfortably tight. Find your size using the chart below. If your measurement falls between sizes, order a size up; you can always add a bit of padding in the sweatband to achieve the perfect fit.