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The average weight and height of 1 year olds (12-18 months) 

The average weight and height of 1 year olds (12-18 months) 

How much do 1 year olds weigh on average? And, linked with that, what is the average 1 year old height for boys and girls?

This article, which draws on anthropometric data from the CDC and the World Health Organization, will give you the weights and heights of children aged 12 to 18 months.

Related Weight/Height Guides:

What is the average weight of a 1 year old boy?

A chart showing the average weight of a 1 year old boy

What is the average weight of a 1 year old boy? According to a National Health and Nutrition Examination Survey, which weighed 268 12 month old baby boys, the average weight for a one year old boy is 25.3 pounds.

In metric units, the average weight of a 1 year old boy is 11.48 kilograms, which works out at 1.8 stones.

Between the ages of 1 and 2, the average one year old boy will gain approximately 5lbs of body weight.

After a baby has turned one, you don’t need to weigh them more than once every 3 months, according to the NHS. [1]

The above 1 year old weight chart shows you the World Health Organization (WHO) percentile data for 12 month old boys so that you can see how your son’s weight compares to that of other boys his age.

What is the average weight of a 1 year old girl?

A chart showing the average weight for a 1 year old girl

What is the average weight of a 1 year old girl? According to data from American anthropometric research, the average weight of a 1 year old girl is 24.1 pounds.

In kilograms, the average weight for a 1 year old girl is 10.93 kg, which works out at 1.72 stones.

As with 12 month old boys, the average one year old girl will gain approximately 5 lbs between the ages of one and two.

Similarly, the weight percentiles for 12 month old girls show the distribution of body weights across the population. So, if a one year old girl’s body weight put her in the 50th percentile, then she’d weigh more than 50% of 1 year old girls.

What is the average height for a 1 year old boy?

A chart showing the average height for a 1 year old boy

What is the average height for a 1 year old boy? Based on data from the World Health Organization, the average height of a 1 year old boy is 75.7 cm or 29.8 inches tall. [2]

In feet, the average height of a 12 month old boy is just under 2 feet 6 inches.

This data is also the recommended reference point by the CDC for children aged 0-2. The figures represent how a child should grow given the optimal conditions.

What is the average height for a 1 year old girl?

A chart showing the average height of a 1 year old girl

What is the average height for a 1 year old girl? According to WHO data, the average height of a 1 year old girl is 74 cm, which is equal to 29.13 inches tall.

In feet, the average height of a 12 month old girl is just over 2 feet 5 inches tall.

The above 1 year old height chart shows you the height percentiles for 12 month old girls. With it, you can see how tall or short your daughter is in comparison with other children.

Of course, some children naturally grow faster or slower than others, and, given the fact that height is largely genetic, especially after age 2, not all 12 month old children will be the exact same height.

What’s the average weight for a 13 month old baby?

A chart displaying the average 13 month old weight for boys and girls

What’s the average weight for a 13 month old baby? According to WHO data, the average weight of a 13 month old boy is 21.61 lbs (9.8 kg), and the average weight of a 13 month old girl is 20.2 lbs or 9.16 kilograms.

As for length and height, the average height of a 13 month old boy is 76.9 cm (30.27 inches), and the average height of a 13 month old girl is 75.2 cm or 29.6 inches.

What is the average 14 month old weight for boys and girls?

A chart displaying the average 14 month old weight for boys and girls

What is the average 14 month old weight for boys and girls? Based on the data, the average weight for a 14 month old is 22.3 lbs or 10.1 kilograms for boys and 20.7 lbs or 9.4 kilograms for girls.

In terms of length and height, the average height of a 14 month old is 78 cm (30.7 inches) for boys and 76.4 cm (30 inches) for girls.

How much should a 15 month old weigh?

A chart showing how much a 15 month old should weigh

How much should a 15 month old weigh? According to WHO Child Growth Standards, the average weight for a 15 month old is 22.7 lbs (or 10.3 kg) and 21.2 lbs (or 9.6 kg) for girls. [3]

Length-wise, the average height for a 15 month old is, based on the same source, 79.1 cm (30.1 inches) for boys and 77.5 cm (30.5 inches) for girls. 

How much should a 16 month old weigh?

A chart displaying the average 16 month old weight for boys and girls

How much should a 16 month old weigh? Statistically, the average weight for a 16 month old is 23.15 lbs (or 10.5 kg) for boys and 21.6 lbs (or 9.8 kg) for girls.

Similarly, the average height for a 16 month old is 80.2 cm (or 31.5 inches) for boys and 78.6 cm (or 30.94 inches) for girls.

What’s the average weight for a 17 month old?

A chart showing the average 17 month old weight for boys and girls

What’s the average weight for a 17 month old? According to the data, the average weight of a 17 month old is 23.66 lbs (10.73 kg) for boys and 22.1 lbs (10.02 kg) for girls.

As for height and body length, the average height for a 17 month old is 81.24 cm (31.98 inches) for boys and 79.67 cm (31.36 inches) for girls.

What is the average weight and height for an 18 month old?

A chart showing the average 18 month old weight for boys and girls

According to the standard growth charts from the World Health Organization, the average weight of an 18 month old boy is 24.12 pounds, which works out at 10.93 kilograms.

Similarly, the average 18 month old weight for a girl is 22.56 pounds, which is equal to 10.23 kilograms.

Next, the average height of an 18 month old boy is 82.25 cm (32.28 inches), while the average height of an 18 month old girl is 80.7 cm (31.74 inches)

Conclusion: How much should a 1 year old weigh?

A person checking how much 1 year olds weigh

So, how much should a 1 year old weigh? From the CDC data, we know that the average 1 year old weight is 25.3 lbs for boys and 24.1 lbs for girls.

These weights differ slightly from the WHO guidelines, which, based on the 50th percentile, are 21.27 lbs for 12 month old boys and 19.73 lbs for 12 month old girls.

As such, it’s important to see a pediatrician if you have any concerns about your child’s physical development.

References

  1. NHS website. (2022, August 26). Your baby’s weight and height. nhs.uk. Retrieved from https://www.nhs.uk/conditions/baby/babys-development/height-weight-and-reviews/baby-height-and-weight/
  2. Growth Charts – Data Table for Boys Length-for-age and Weight-for-age Charts. https://www.cdc.gov/growthcharts/who/boys_length_weight.htm
  3. WHO Child Growth Standards. World Health Organization. https://cdn.who.int/media/docs/default-source/child-growth/child-growth-standards/indicators/weight-for-age/wfa-girls-0-5-percentiles.pdf