Premature, PM

4.4–9 lbs. / 2–4 kg

Newborn, NB

0–1 months
6.5–13 lbs. / 3–6 kg

Small, S

1–3 months
11–17 lbs. / 5–8 kg

Medium, M

3–6 months
15–22 lbs. / 7–10 kg

Large, L

6–15 months
20–26 lbs. / 9–12 kg

Extra Large, XL

15–24 months
24–30.5 lbs. / 11–14 kg

Super Large, SL

24+ months
28+ lbs. / 13+ kg