This headband is one size fits most and the size cannot be adjusted. The headband is sewn at a 6.5" diameter (13" circumference), keep in mind that measurement is before it stretches. The soft nylon fits a newborn and can stretch comfortably as she grows into childhood. The bow measures approximately 4.5" across. This style is secured with adhesive once tied and is not meant to be untied. Due to the nature of small-batch production color and sizing can vary slightly.