During this second year of life, your toddler may gain between 3 and 5 pounds (1.4 to 2.26 kilograms). An average 15-month-old girl weighs about 22 pounds (about 10 kilograms) and stands 31 inches (79 centimeters) tall. Boys tend to be about a pound heavier at 15 months but about the same height.
By age 2, both will stand about 34 inches tall (86 centimeters) and weigh about 27 to 28 pounds (12.25 to 12.7 kilograms) on average. Your toddler's head size also will not change as dramatically this year, with about 1 inch (2.54 centimeters) added to head circumference.
What you will notice more than actual growth are changes in a toddler's appearance. Instead of sporting the rounded belly and soft arms and legs suited to crawling on all fours, toddlers start to trim down, become more muscular because of increased activity, and begin to look more like preschoolers than babies.