It isn't hard to figure out how big your Maltese puppy will grow. The breed standard for this small white dog limits weight to just 7 pounds at maturity and states that 4 to 6 pounds is preferred. If you don't show your dog, an extra pound or so is acceptable -- but more than that probably indicates obesity and its attendant health risks. The standard doesn't call for a height limit, but most Maltese dogs mature between 8 and 10 inches high at the shoulder.
Meet the Parents
Perhaps the best way to determine the eventual size of your Maltese puppy is to meet the parents. If you buy from a breeder, note the mother's size when you inspect her. If the father isn't on the premises, the breeder should be able to provide you accurate information about his size. A Maltese puppy born to exceptionally small or large parents will likely mature at either end of the size scale for the breed.
Caring for Your Puppy
Although genetics greatly influence a dog's adult size, they way you care for the Maltese puppy also plays a role. Feed your Maltese a high-quality food recommended by your veterinarian, and make sure she gets plenty of exercise -- the Maltese is more active than many other small dogs. Consult your vet if your pet exceeds 7 pounds -- if she doesn't need a diet or more exercise, she might have an illness that needs addressing.