There are two sizes of Trucker Hats available for order Adult and Youth. Youth hats are overall about 20% smaller than the adult hats.
Adult hats are for head sizes from 20" to 25"
Youth hats are for head sizes from 19" to 23"
Measure Your Head
Measuring for your head size is both an art and a science. 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.