The bust is measured from underarm seam to underarm seam across the front. Double to get the circumference. The length is measured from the shouldler seam straight down to the hem at the shortest point and at the longest point.  A size 1 is a Small/Medium and a size 2 is a Large/X-Large.
1: Bust is 21.5" (43" around). Shortest Length is 45", longest length is 50.5"
2: Bust is 24.5" (49" around). Shortest Length is 46", longest length is 51.5"