It depends on the show. I believe 18 in.
how tall pony
If you are too tall for a pony, ride a horse instead.
a pony is a horse under 14.2 hands tall.
Matt Hunter is about 5'10- 5'11 feet tall
pony
Hunter Teran is 6'.
Hunter Emery is 6'.
Hunter Clary is 4'.
Hunter Fite is 6'.
Hunter Pecunia is 5'.
Hunter McGilvray is 6'.
Johny Hunter is 6'.