1. What is BMI for Children?

BMI (Body Mass Index) for children and teens is calculated the same way as for adults, but the results are interpreted differently. For children, BMI is age- and sex-specific because their body composition varies as they grow.

2. How BMI is Calculated for Children

The calculator uses the standard BMI formula:

Where:

• \( weight \) — Body weight in kilograms
• \( height \) — Height in meters

Explanation: The result is then compared to growth charts for children of the same age and sex to determine the percentile.

3. Understanding BMI Percentiles

Details: Percentiles show how a child's BMI compares to others of the same age and gender:

• Below 5th percentile: Underweight
• 5th to 85th percentile: Healthy weight
• 85th to 95th percentile: Overweight
• Above 95th percentile: Obese

4. Using the Calculator

Tips: Enter weight in kg, height in meters, age in years (2-18), and select gender. For accurate results, measurements should be taken by a healthcare professional.

5. Frequently Asked Questions (FAQ)

Q1: Why is BMI different for children than adults?
A: Children's body fat changes with age and differs between boys and girls, so BMI must be interpreted relative to other children of the same age and sex.

Q2: What if my child is very muscular?
A: BMI may overestimate body fat in muscular children. A healthcare provider can perform additional assessments if needed.

Q3: How often should my child's BMI be checked?
A: The NHS recommends annual BMI checks for children as part of routine health assessments.

Q4: What should I do if my child's BMI is high?
A: Consult your GP or a pediatrician for personalized advice. They may recommend dietary changes, increased physical activity, or further testing.

Q5: Where can I find official NHS growth charts?
A: NHS growth charts are available on the NHS website and through healthcare providers.