Miniature poodles can grow to a maximum of 15 inches at the shoulders, according to the American Kennel Club breed standards. Note that miniature is a size class within the poodle breed, not a breed unto itself.
The poodle is a breed of domesticated dog with tightly curling hair. It comes in several size classes: standard, miniature and toy. Dogs in all size classes are held to the same breed standard. Any dog above 15 inches in height at the shoulders is considered a standard poodle, rather than a miniature. Miniatures are defined as dogs that stand between 15 and 10 inches high. Toy poodles are any adult poodles under 10 inches in height.