Average Weight & Height for a 1-Year-Old (12 Months)

Growth at 12 Months

The first birthday is a major milestone! By 12 months, most babies have tripled their birth weight and grown about 25 cm (10 in) since birth. The average 1-year-old boy weighs about 10.5 kg (23.1 lb) and measures 76.1 cm (30 in). Girls average 9.7 kg (21.3 lb) and 74.4 cm (29.3 in).

Growth Slows After the First Year

After the rapid growth of infancy, toddlers grow much more slowly. In the second year, children typically gain only 2–3 kg (4.4–6.6 lb) and grow about 12 cm (5 in) in height. This natural slowdown often comes with decreased appetite, which is completely normal. Don't worry if your toddler seems to eat less than they did as a baby.

Transitioning Growth Charts

At 2 years, pediatricians often switch from measuring recumbent length to standing height, which can cause an apparent decrease of about 1 cm. They also transition from WHO growth charts (used for 0–2 years) to CDC growth charts (used for 2–20 years). Our calculators handle these transitions automatically.

First Birthday Milestones

At 12 months, many children are taking their first steps, saying their first words, and using objects purposefully (like drinking from a cup). Physical growth and developmental milestones go hand in hand — track both with our milestone tracker and growth tracker.