Both Maltese and Maltipoo dogs are considered to be in the Toy size class. The Maltese, being recognized, is officially a toy sized dog with his weight of 4 -7 lbs (1.81 - 3.18 kg). The Maltipoo, although not recognized, does fit this classification. The smallest toy is the Chihuahua with a top weight of 6 lbs. (2.72 kg) and the largest is the Pug with a weight of 14 to 18 lbs. (6.35 to 8.16 kg) Most Maltipoos range from 5-12 lbs. (2.27-5.44 kg), putting him correctly in the category of toy sized.
The size of a Maltipoo
depends on if a toy Poodle is a parent and what weight that dog was (6 to 9 lbs. - 2.72 to 4.08 kg) or a mini is one of the parents (15 to 17 lbs. - 6.8 to 7.7 kg).
Since most Maltese will only be 7 lbs. at the most and some Maltipoo are as tiny as 5 lbs., there are some Maltipoo that are smaller than Maltese dogs. However, since many Maltipoo dogs are typically in the 8 to 10 pound range(3.62 to 4.53 kg) and they can grow to be as large as 12 lbs. (5.44 kg). (these are often the ones that have a miniature Poodle as a parent), the majority of Maltipoo will be slightly larger than Maltese dogs.
In regard to height, which is measured from the withers (the top of the shoulder blades) to the floor, both Maltese and Maltipoo have a starting range of 8 inches (20.32 cm). Maltese can mature to be as tall as 10 inches (25.4 cm) and Maltipoos may be a bit taller, sometimes as tall as 14 inches (35.5 cm).
So, on average, a Maltipoo may be slightly larger than a Maltese in both weight and height, however is still considered to be a small lap dog.