When trying to decide between two sizes, choose the larger size for a better fit.

Size Size/Age Range Chest Height Weight
0-6 Months Newborn-6 months 8 3/4" 12 1/2" 5.0 oz
6-12 Months 6 Months-12 Months 9 3/4" 13 1/2" 5.0 oz
12-18 Months 12 Months-18 Months 10 3/4" 14 1/2" 5.0 oz
18-24 Months 18 Months-24 Months 11 3/4" 15 1/2" 5.0 oz
2T 2 Years 13" 15 1/2" 4.5 oz
3T 3 Years 14" 16 1/2" 4.5 oz
4T 4 Years 15" 17 1/2" 4.5 oz