The size 8/ S in Ralph Lauren is closest to the following:
Brand Label Weight (lbs) Height (inches)
American Apparel 10 years 54 - 62 lbs 51 - 54 inches
Burt's Bees Baby (Target) 7 53 lbs 48 - 51.5 inches
H&M 7-8 years - 50 inches
Hanna Andersson 130cm 52 - 64 lbs 50 - 54 inches
Hatley 8 - 53 inches
J.Crew/ Crewcuts 7 54.5 - 63.5 lbs 49 - 52 inches
LLBean 8/S - 49 - 52 inches
Marimekko 9 yrs/143 cm - 53 inches
MiniBoden 9y - 53 inches
Petit Bateau 12Y 54 - 58 lbs 59 inches
Ralph Lauren 8/ S 55 - 62 lbs 52 - 54 inches
tea 7/M 51 - 61 lbs 48 - 51 inches