Size 3M 6M 9M 12M 15M 18M 21M 24M Romper Shoulder 18.5 19 19.5 20 21 21.5 22 22.5 Chest 46.7 48.2 49.5 50.5 52 53 54.5 56 Length 37 38 39 40 42 43.5 45.5 47.5 Sleeve(Short) 7.9 8.2 8.5 8.8 9.2 9.5 9.8 10