The Average Height and Weight for a 3-Year-Old

By Erica Loop
A three-year-old toddler on a swing in the park.
A three-year-old toddler on a swing in the park.

Your 3-year-old is outgrowing his toddler tummy and looking more and more like a big kid. If you’re wondering what to expect when it comes to his size, understanding growth trends and the percentiles for this age can answer your questions.

Growth Charts

There isn’t just one height and weight number for your 3-year-old. Instead, there is a range of percentiles that your child may fit into. These growth charts provide comparisons between your child and other kids the same age and sex. Boys and girls have different growth charts, as do children of different ages. The percentile numbers indicate where your child falls in terms of height and weight. A percentile number doesn’t tell you that your child is too short, too tall or not an average weight. It says where she falls in the continuum of kids’ sizes. For example, if he’s in the 75th percentile for height, he is taller than 75 percent of 3-year-olds.

The doctor may look for a pattern across her growth charts, and not for how she compares to other children. This shows whether your child's growth is progressing at a steady rate.

Weight for Boys and Girls

Your 3-year-old son’s weight may fall from just under 30 pounds to slightly less than 40 pounds, according to the U.S. Centers for Disease Control and Prevention’s growth charts. This gap represents the variations that are all normal for a young preschooler. On average, children gain five pounds from ages 3 to 4, according to the American Academy of Pediatrics.

If your child is under 30 pounds or doesn’t gain enough weight during his third year, talk to his doctor. Likewise, if your child weighs more than 40 pounds or gains more than five pounds in his third year, ask if you should be concerned. Your child’s pediatrician can look for potential weight loss or gain causes, and inform you of ways to help your child eat a healthy, nutritious diet.

Just like boys have a range of weights, so do girls. During the third year, your daughter should weigh between 27 and 37 pounds, according to the CDC’s growth charts.

Average Height

Height also varies among children of the same age. At age 3, a boy’s height averages from 35 to 40 inches and a girl’s is between 35 and 39 inches, according to the CDC. On average, children grow 3.5 inches between 3 and 4.

Physical and Motor Growth

As your child grows physically, he’s also developing motor skills. His increased size and muscle tone allow him to hop, stand on one foot, walk up and stairs without your help, throw and kick a ball and move both forwards and backwards

About the Author

Based in Pittsburgh, Erica Loop has been writing education, child development and parenting articles since 2009. Her articles have appeared in "Pittsburgh Parent Magazine" and the website PBS Parents. She has a Master of Science in applied developmental psychology from the University of Pittsburgh's School of Education.