The goal of this study was to measure the arm circumferences (AC) and appropriated cuff sizes for children and adolescents and to relate these dimensions to specific age ranges. This is a cross-sectional study, developed in Fortaleza, Ceará, Brazil, with 596 people between 6 and 17 years old. The AC was measured at the midpoint between the olecranon and the acromion. The selected cuff width followed the recommended ratio of 40% the AC. The more suitable cuff sizes were 7x14 cm, 8x16 cm and 9x18 cm, at 19.8%, 26.5% and 25%, respectively. A statistically significant association between AC and age range was found in both genders, as well as between the cuff and the age range, showing that the 7x14 cm (38.9%) and 8x16 cm (29.6%) cuffs were more suitable for children, and 8x16 cm (23.7%) and 9x18 cm (36.1 %) cuffs were better for adolescents. Adequate cuffs were concluded to be different from the standard cuffs used for children and adolescents.