HAT SIZE CHART
How to Measure your Head & Hat Sizing
It is important to be able to measure your head correctly to get a well fitting hat. Use a tape measure to determine the length. Place the tape around your head about 3mm above your ear, across the mid-forehead, completely circling your head. Measure firmly, but not too tight where the hat would sit across your forehead. If you are in between two sizes, choose the bigger size. You can always pad a hat smaller.
Another valid method to determine hat size is to try on a hat 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 hats. Sizes, even though they do vary depending on the hat maker, are technically universal. You may refer to the hat size chart below.