These unique custom MADE TO ORDER hats are truely one of a kind. Not all heads are created equal , which is why we have so many size options. You can customize your hat color, size and your favorite design. please note all hat colors vary by size, in other words- not every hat color is available in every size. **please note these are made to order and the design layouts will be unique to each hat ordered** Please feel free to ask any questions you have about sizing, as these are MADE TO ORDER exactly how the order is placed, I do not offer refunds or exchanges, thanks you! The "extra small" size measures(SnapBack). measures about 6" deep and 18-22" in diameter(depending on where you adjust the straps)- I recommend this size for ages 18 months-4. The "small" (former toddler/youth) measures about 6" deep and 18-23" in diameter(depending on where you adjust the straps)- I recommend this size for ages 4-8 years old. The "small-med"(former women's small)is a youth size and measures measures about 6.5" deep, and is adjustable(snapback) from about 20"-23" around. I recommend this for ages 8 and up to adults with petite heads or that like a tighter fitting hat. The Medium(NOT AVAILABLE IN SOME DESIGNS) Is an adult fit measuring 6.5" deep and measures about 22-24" around depending on where you adjust the snaps. The med-large(former) regular size is about 7"deep and measures about 22-25" around depending where you adjust the snaps.