Here's height comparison of Equestria Girls Mane Six.

Most people argue about popular height headcanon of humanized Mane Six especially Fluttershy as tall and while Rainbow Dash as short but i'm disagree with that headcanon and also my height headcanon of humanized Mane Six especially Rainbow Dash depicted as tallest girl (because she very athletic and more protein to get stronger and taller) and Fluttershy depicted short (because she shared her same height and likeness with her voice actress) alright here's other 4 Equestria Girls Mane Six heights with shared their voice actresses height according to some sources, but some of little bit different (due in fact some characters like Rainbow Dash and Applejack are voiced by Ashleigh Ball and Pinkie Pie and Fluttershy are voiced by Andrea Libman)

Here's chronological order from shortest to tallest.
Fluttershy = 5'1 (the shortest of mane 6 also she shared same height like her voice actress)
Pinkie Pie = 5'2 (she's 1 inch taller than Fluttershy)
Rarity = 5'2 (shared same height with her voice actress also why i'm make Rarity look shorter because she wearing heels)
Twilight Sparkle = 5'3 (although she's very little bit half inch taller than her voice actress)
Applejack = 5'5 (shared same height with her voice actress)
Rainbow Dash = 5'10 (the tallest of mane 6 also she 5 inch taller then Applejack)

Sunset Shimmer height is unknown due her voice actress height is unknown so in my headcanon she'll be 5'8 similarly to Rainbow Dash.

However Sunset Shimmer wasn't include here but she'll appeared later.

Here's the credits below for original vectors that i used.
All of Mane Six by @rupahrusyaidi
Blank height chart by @swiftgold (heavily edited by me)