Infants, Toddlers, & Kids
Size
(approx)
Alpha Height in Inches Weight in lbs Age Chest in Inches Waist in Inches
Newborn   up to 18" up to 7 lbs Newborn up to 15  up to 15
0-3m   18-22" 7-11 lbs 0-3 mos 15 - 16 1/2 15  - 18
3-6m   22-25" 11-15 lbs 3-6 mos 16 1/2 - 17 1/2 18 - 18 1/2
6-9m   25-27" 15-18 lbs 6-9 mos 17 1/2 - 18 18 1/2 - 19
9-12m   27-29" 18-22 lbs 9-12 mos 18 - 18 1/2 19 - 19
12-18m   27-31" 18-26 lbs 12-18 mos 18 1/2 - 19 1/2 19 - 19 1/2
18-24m   29-33" 22-29 lbs 18-24 mos 19 1/2 - 20 1/2 19 1/2 - 20
2 XXS 31-34" 26-29 lbs 1-2 yrs 20 1/2 20   
3 XXS 34-38" 29-33lbs 2-3 yrs 21    20 1/2
4 XS 38-42" 33-37 lbs 3-4 yrs 22    21   
5 S 42-45" 37-43 lbs 4-5 yrs 23    21 1/2
6 S 45-48" 43-50 lbs 5-6 yrs 24    22   
7 M 48-51" 50-57 lbs 6-7 yrs 24 3/4 22 1/2
8 M 51-54" 57-67 lbs 7-8 yrs 27    23   
10 L 54-57" 67-75 lbs 8-9 yrs 28 1/2 24   
12 L 57-60" 75-85 lbs 9-10 yrs 30    25   
14 XL 60-62" 85-100 lbs 10-11 yrs 31 1/2 26   

How to Measure Kid and Toddler Sizes:

Measuring Guidelines for Kids and Toddlers Height Stand child with feet slightly apart and their back to a wall. Measure from the floor to the top of their head for height. Measure child without shoes for best results.
Chest With arms relaxed at sides, measure child around the fullest part of their chest. Keep tape measure parallel to the floor.
Waist Standing straight up, measure child's natural waist. Keep tape measure comfortably loose and parallel to the floor.

How to Measure Infant Sizes:

Measuring Guidelines for Infants Height While lying down and legs extended, measure infant from top of head to bottom of feet.