Kids Baseball Hats come in a variety of colors and sizes. The size scale is APPROXIMATE. Our hats do run small, so when in doubt size up! The Baby trucker Hat - Itty Bitty is 45 CM (fits most 4-12 Months). The Toddler Trucker Hat -Mini is 49 CM (fits most 12-24 Months). The Kids Trucker Hat - Kiddo is 52 CM (fits most 2-5 Years). The Youth Trucker Hat- Youth is 54 CM ( fits most 5-7 Years). The Big Kid Trucker Hat- is 57 CM ( fits most 8 Years - Adult).