BMI at age 14
Enter an age, a sex, a height and a weight to see BMI for age. The example below uses a boy aged 14 at 5 ft 5 in and 115 lb.
How it works
First the page works out BMI: weight in kilograms divided by height in meters squared. Then it reads L, M and S from the CDC table for this age and sex. It finds z as ((BMI divided by M) to the power L minus 1) divided by (L times S) and turns z into a percentile. For males at age 14 the 5th, 85th and 95th percentile BMI values are 16.0, 22.7 and 26.0.
Worked example
A boy aged 14 is 165.1 cm tall and weighs 52.163 kg. Square the height: 1.6510 × 1.6510 = 2.7258. Divide 52.163 by 2.7258 to get a BMI of 19.1368. The male table at this age has L -2.2274, M 19.158 and S 0.13525. 19.1368 divided by 19.158 = 0.998893. Raise 0.998893 to the power -2.2274 to get 1.002470. Subtract 1 to get 0.002470. 0.002470 divided by (-2.2274 × 0.13525) = -0.008. That z score is the 50th percentile, which is healthy weight.
At age 14, a boy and a girl each at the CDC median height and the weight that gives the median BMI. The form above is set to the boy.
- Male at median height and weight (5 ft 5 in, 115 lb)
- BMI 19.1, 50th percentile
- Female at median height and weight (5 ft 3 in, 109 lb)
- BMI 19.3, 49th percentile
Common questions
What do the percentile bands mean?
Below the 5th percentile is underweight. From the 5th up to the 85th is a healthy weight. From the 85th up to the 95th is overweight. The 95th and above is obesity. At age 14 the 5th, 85th and 95th percentile BMI values for males are 16.0, 22.7 and 26.0.
What is the median BMI at age 14?
On the CDC chart the median is 19.2 for males and 19.4 for females at age 14. The example BMI of 19.1 is 0.0 away from the male median of 19.2.
Does BMI show body fat in a child?
Only roughly. BMI uses height and weight. A muscular child can score high. A doctor looks at growth over time as well as the number. A BMI of 19.1 for this boy at age 14 says nothing about how much of the 115 lb is muscle.
Why does BMI change as a child grows?
BMI usually falls through early childhood and then rises through the teen years. That is normal growth, which is why the chart is built by age. The median BMI for males is 19.2 at age 14.
What should I do if my child is above the 85th percentile?
One reading is not a diagnosis. Raise it with your child's doctor, who can look at growth history and the whole picture. The 85th percentile BMI for males at age 14 is 22.7.