The Dog Breed Info Center lists an average weight for Maltese dogs as being between 6 1/2 and 9 pounds. The American Kennel Club breed standard insists that show quality dogs be under 7 pounds, with an adult weight between 4 and 6 pounds preferred.
The other two main breed standards currently in use for the Maltese are the UK Kennel Club standard and the FCI, a group based out of Belgium that is known in English as the World Canine Organization. As reported by DogWorld SA, the UK standard does not list any weight at all for the breed. The FCI, on the other hand, lists a higher show-quality weight than the American Standard, anywhere between 6.6 and 8.8 pounds.