Previous guidelines suggested that children age 2 to 6 years require a shoe size change every 1 to 2 months. Our study of foot growth in 112 children enrolled in a prospective treatment protocol for flatfoot demonstrates that children age 12 to 30 months will require shoe size change every two to three months but that foot growth slows over the subsequent four years, necessitating shoe size change only every 4 months in children up to 4 years of age and every 6 months in children from age 4 to 6 years.