Items are handmade with attention to detail in my smoke free, pet free home. This hat measures 17" in circumference and 6 1/2" from crown to brim, and should fit a month old. Hats have some additional ease in circumference due to the stretchy nature of yarn. This cozy hat is made with super soft, chunky yarn. Approx. sizing: Newborn: 5" crown to brim, 12-13" head circumference 0-3 months: 6" crown to brim, 14-16” head circumference 3-6 months: 6” crown to brim, 16-17” head circumference 6-12 months: 7” crown to brim, 16-18” head circumference 12-18 months: 7" crown to brim, 18-19" head circumference Head sizes vary, but this will give you an idea. You can measure around your child's head for circumference, and from the top of the head down towards the ear for length. Note: I do my best to have the photos portray colors accurately, but please note colors may vary slightly due to computer monitor settings or lighting. Care instructions: Hand wash in cool water, do not wring or twist, lay flat to dry.