The Shih Tzu is a snugly built little animal with a solid, sound structure. It stands from about 8 to 11 inches tall at the withers, and should weigh from 9 to 16 pounds. Its body length is slightly greater than its height, and it should be physically proportional all over, neither too short or too small, but a true miniature breed dog. In movement, it moves with effortless, smooth strides, showing good drive and reach, with the head and tail held high, giving away its ancient royal bloodlines.
Its hair is double layered, full, dense, and lush, and grows long and straight, past the feet. The Shih Tzu sheds very little, making it a good choice for people who have light allergies to fur, or for people who just prefer not to clean up a lot of hair. Regular grooming is a requirement with this breed because of this characteristic; the hair will get tangled and matted quickly as it gets longer. The ears and tail are full and long, with the tail hair fluffing it out in a feathery plume that curves over the back.
This breed is categorized as brachycephalic, meaning that the muzzle and nose of the Shih Tzu is flat, though not as flat as its cousin, the Pekingese. The eyes are round and wide, but in contrast to some other flat muzzled dogs, the eyes should not bulge or be too prominent. The Shih Tzu should have an innocent, wide-eyed, warm expression giving it an impression of friendliness and trustworthiness, rather than the more ferocious appearance of the Pekingese.