Healthy BMI for Children (Ages 2–19)

 

A healthy BMI for children is based on age- and sex-specific percentiles, not fixed numbers like in adults. This is because children grow at different rates.

✅ Healthy BMI for Children (Ages 2–19):

• Underweight: Below the 5th percentile

• Healthy weight: 5th to less than 85th percentile

• Overweight: 85th to less than 95th percentile

• Obese: 95th percentile or above

These percentiles are calculated using the CDC BMI-for-age growth charts.

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🧮 How to Calculate It:

1. BMI formula:

   $$\text{BMI} = \frac{\text{weight (kg)}}{\text{height (m)}^2}$$

   or

   $$\text{BMI} = \frac{\text{weight (lb)} \times 703}{\text{height (in)}^2}$$

2. Plot on CDC growth chart based on age and sex to find the percentile.

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📌 Why It Matters:

BMI helps screen for weight-related issues, but it’s not a diagnosis. Muscle, bone structure, and other factors can affect results. Pediatricians consider the whole picture—growth trends, family history, and activity levels.