General Physical Traits

Twilight Sparkle (Non Alicorn)
-Height: 5’0”
-Weight: 95 lbs
-Bust: 30B
-Waist: 24
-Hips: 35

Rarity
-Height: 5’9”
-Weight: 130 lbs
-Bust: 36D
-Waist: 26
-Hips: 37

Fluttershy
-Height: 5’11”
-Weight: 140 lbs
-Bust: 36DDD
-Waist: 27
-Hips: 38

Rainbow Dash
-Height: 5’2”
-Weight: 125 lbs (ALLLL MUSCLE!!!!)
-Bust: 32 C
-Waist: 25
-Hips: 36

Pinkie Pie
-Height: 5’10”
-Weight: 210 lbs (No pony eats that much sugah without being curvy. That booty though)
-Bust: 40DD
-Waist: 36
-Hips: 43

Applejack
-Height: 6’0” (6'2" with hat and boots)
-Weight: 190 lbs
-Bust: 38C
-Waist: 30
-Hips: 40

Eric:
-Height: 6’2”
-Weight: 205 lbs
-Chest: 40
-Waist: 36

Author's Note

I wanted to do one of these so you can get an apt picture of what the characters look like next to each other. I always imagined Twilight was the shortest and Applejack the tallest. Fluttershy's height and hourglass figure making her the model Photo Finish wanted. Rainbow's obvious shortness led to her almost unhealthy desire to win at everything and why Applejack was convinced she could beat Rainbow Dash at anything. While Pinkie is relatively curvaceous her bouncing and running keep her from being enormous. Eric being an RSR for Oroweat and a metal forger was always going to be a big dude. For future reference Twilight's Alicorn Anthro form would be VERY Statuesque. Later I'll include another list for the Alicorns and Discord.