Check out our new baby trucker hat! Show the baby in your life how grateful you are and get them one of these colorful old school foam truckers. Features a velcro back for easy and fast adjustability. Infant Fit NB - 6M - 0-6 months 15.5-17.5", 39.37 - 44.45 cm Toddler Fit 6M - 2 Yrs - 6-24 months 17.5-20", 44.45 - 50.8 cm Measuring 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. Check out our new baby trucker hat! Show the baby in your life how grateful you are and get them one of these colorful old school foam truckers. Features a velcro back for easy and fast adjustability. This comes in two sizes! Infant Fit NB - 6M #HILNBL Toddler Fit 6M - 2 Yrs #HTLNBL Definitely use measurements, NOT age, to guide you. Munchkin heads come in all sizes for all ages. 0-6 months 15.5-17.5" 39.37 - 44.45 cm 6-24 months 17.5-20" 44.45 - 50.8 cm Measuring 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.