BMI at age 16
Adult BMI bands do not apply at age 16. The form below gives a percentile for age and sex, and the example walks through one case.
How it works
BMI is weight in kilograms divided by height in meters squared. For a child that number is scored against the CDC table. M is the median BMI for the age and sex. L and S set the shape of the spread. The z score and percentile follow from all three. At age 16 the median BMI is 20.6 for males and 20.5 for females. This male example is 0.0 from its median.
Worked example
For a boy aged 16 at 5 ft 8 in and 135 lb, height is 1.7272 m and weight is 61.235 kg. Square the height: 1.7272 × 1.7272 = 2.9832. BMI is 61.235 divided by 2.9832, which is 20.5266. The CDC values are L -2.0390, M 20.558 and S 0.13420. Divide the BMI by M to get 0.998473. Raise that to the power L to get 1.003121. Subtract 1 to get 0.003121. Divide by L × S to get z = -0.011. The 50th percentile falls in the healthy weight band.
At age 16, 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 8 in, 135 lb)
- BMI 20.5, 50th percentile
- Female at median height and weight (5 ft 4 in, 119 lb)
- BMI 20.4, 50th percentile
Common questions
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 16 is 24.2.
Which ages does this calculator cover?
It covers ages 2 to 20, the range of the CDC growth charts. For adults over 20 use the adult BMI calculator. This page reads the CDC male table at 192.5 months.
Why does a child BMI use percentiles and not the adult bands?
Children grow, and a healthy BMI changes with age and differs between males and females. A percentile shows where a child sits among others of the same age and sex. At age 16 the median BMI is 20.6 for males and 20.5 for females, and the example boy sits at the 50th percentile.
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 16 the 5th, 85th and 95th percentile BMI values for males are 17.1, 24.2 and 27.6.
What is the median BMI at age 16?
On the CDC chart the median is 20.6 for males and 20.5 for females at age 16. The example BMI of 20.5 is 0.0 away from the male median of 20.6.