GIRLS WORLD BOOK DAY DR PRINCESS FANCY DRESS SIZE GUIDE: SMALL 4/6 YEARS CHEST - 24/26" LENGTH - 29" MEDIUM 7/9 YEARS CHEST - 26/28" LENGTH - 31" LARGE 10/12 YEARS CHEST - 28/30" LENGTH - 34" XLARGE 12/13 YEARS CHEST - 30/32" LENGTH - 36".