Child and Teen BMI Calculator
Calculate Percentile of Your Child and Teens
Children and teens need a different BMI assessment than adults. This calculator uses CDC BMI-for-age growth charts to compare your child’s Body Mass Index (BMI) with children of the same age and sex, helping you understand their BMI percentile, growth pattern, and weight category.
Age Range
2 – 18 Years
Growth Assessment
Underweight, Normal, Overweight, Obese
BMI Percentile
CDC Growth Chart
Input Result
Date of birth, Weight and Height
Result
< 30 seconds
Calculate Percentile
Child and Teen BMI Calculator
Age 2–18 Years
Results
A single measurement is a snapshot, not a trend. BMI-for-age percentiles indicate how this measurement compares with other children of the same age and sex — they don't by themselves indicate a health problem. A pediatrician can interpret these numbers alongside your child's growth history.
History
Chidren BMI
This calculator uses your child’s height, age, and gender to check whether they are at a healthy weight. Children’s BMI is measured with a percentile calculator, which compares them to other children of the same age and sex (unlike adults, whose BMI is measured differently), as recommended by the Centers for Disease Control and Prevention. Child are always growing, so their BMI will change, and it should be viewed as a trend, not a single number. It’s a useful screening tool, but it’s essential to consult a doctor for proper interpretation of a child’s growth and overall health.
Teen BMI
A BMI calculator for teens helps determine if a teen’s weight is healthy, taking into account their height, age, and gender. Instead of fixed numbers, it uses percentile charts to compare teens with others of the same age. Although the formula is the same for both, boys often have more muscle while On average, girls have a higher share of body fat and boys more muscle, which can affect BMI. However, BMI does not directly measure body fat, so it may not always provide a complete picture. Some teens may have a higher BMI due to muscle mass or body type, while others with a normal BMI may still have more body fat. During puberty, quick weight gain is also normal and can affect results. That’s why BMI should be viewed over time, not just as a single number; it’s best to consult a healthcare professional for a proper understanding.
BMI Table For Children and Teens( Age 2-20)
This BMI table helps parents understand whether a child’s weight is healthy for their age and height. It uses BMI percentiles to know a child is underweight, at a healthy weight, overweight, or obese, along with possible health risks.
| Percentile Range | Category | What It Means |
| Below 5th | Underweight | BMI is lower than most children of the same age and sex. A doctor can check growth. |
| 5th to less than 85th | Healthy Weight | BMI is within the typical range for age and sex |
| 85th to less than 95th | Overweight | BMI is higher than most children of the same age and sex. Worth watching over time. |
| 95th or above | Obesity | BMI is much higher than most children of the same age and sex. Worth discussing with a doctor. |
BMI Z-Score for Children and Teens
A BMI Z-score shows how a child’s BMI compares with other children of the same age and sex. Instead of using only a percentile, the Z-score shows how far your child’s BMI is from the average. A Z-score of 0 means the BMI is exactly average for children of the same age and sex. A positive Z-score means the BMI is above average, while a negative Z-score means it is below average. This helps doctors and parents better understand a child’s growth pattern.
The BMI Z-score is especially useful for tracking growth over time. Even if two children have the same BMI, their Z-scores may differ because they are of different ages or sexes. Healthcare professionals use BMI Z-scores to monitor healthy growth, identify possible underweight or overweight concerns, and follow changes during treatment or regular checkups. It provides a more detailed picture than BMI alone.
Your BMI Z-score should always be considered together with your child’s BMI percentile, age, height, weight, medical history, and overall health. A high or low Z-score does not necessarily indicate a health problem, but it may suggest that further evaluation is needed.