How tall are Luna and Celestia?Someone on :iconEvilSugar:'s page had made an off-hand comment about wondering what a 1:1 scale Luna plush would look like. I set out to figure that out.More Like This
I copied my post from there to here, and then edited it a bit for some dimensions I'd missed.
A pony is defined as being anything under 14 hands tall at the withers (between the shoulder blades). 14 hands equals 56 inches, or 4'8". Assuming that Princess Celestia is the tallest pony in Equestria, as well as the tallest a pony can be while still remaining a "pony", this would place her as being just above eye level with a six foot tall man. An "average" pony in the show would be approximately 3'6" at the eyes.
Luna is shown riding beside Celestia, near the end of the second episode (20:18). While standing next to Celestia, the top of her head is almost exactly level with Celestia's withers, while her horn extends upwards, reaching the level of Celestia's eyes. In other words, Luna is almost exactly six feet tall, from hoof to horn.