The size nb in Wal-Mart is closest to the following:
Brand Label Weight (lbs) Height (inches)
American Apparel 3-6m 7 - 15 lbs 17 - 24 inches
BabyBoden 0-3 months 0 - 13 lbs 0 - 23.5 inches
Burt's Bees Baby (Target) 0-3 M 7 - 12 lbs 18 - 24 inches
Carters nb 5 - 8 lbs 21.5 inches
Cherokee (Target) nb 6 - 8.5 lbs 18 - 20 inches
Circo (Target) nb 6 - 8.5 lbs 18 - 20 inches
Gap 0-3 months 7 - 12 lbs 19 - 23 inches
Gymboree 0-3 7 - 12 lbs 19 - 23 inches
H&M 0-1 - 20 inches
Hanna Andersson 50cm 6 - 12 lbs 18 - 22 inches
Hatley 0-3m 7 - 12 lbs 18 - 23 inches
J.Crew/ Crewcuts Newborn 7 lbs 17 - 19 inches
Jumping Bean (Kohl's) 3 months 8 - 12 lbs 21 - 23 inches
LLBean 0-3m 9 - 14 lbs 22 - 25 inches
Marimekko 3 months/ 62cm - 18 - 22 inches
Old Navy 0-3 7 - 12 lbs 19 - 23 inches
OshKosh 3 months 8 - 12.5 lbs 21.5 - 24 inches
Petit Bateau N/50 6 lbs 19.5 inches
Ralph Lauren 0-3 months 10 lbs 21 inches
The Children's Place 0-3 months 7 - 11 lbs -
Tucker + Tate (Nordstrom) NB 6 - 9 lbs 18.5 - 21 inches
Wal-Mart nb 5.5 - 7.5 lbs 17.5 - 21 inches
Zutano 3m 9 - 12 lbs 18 - 20 inches
childhoods 0-3 months 7 - 12 lbs 18 - 23 inches
janie and jack Newborn 7 lbs 19 inches
tea 0-3 M 8 - 11 lbs 17 - 22 inches