1. What is BMI for Children?

BMI (Body Mass Index) for children is calculated the same way as for adults, but the results are interpreted differently. For children and teens, BMI is age- and sex-specific and is often referred to as BMI-for-age according to NHS guidelines.

2. How Does the Calculator Work?

The calculator uses the standard BMI formula:

Where:

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

Note: For children, the BMI number is plotted on a growth chart to obtain a percentile ranking based on age and gender.

3. Importance of BMI Calculation

Details: BMI-for-age is the recommended indicator for screening overweight and obesity in children and teens. It helps identify potential weight problems that may lead to health issues.

4. Using the Calculator

Tips: Enter weight in kilograms, height in meters, age in years (2-18), and select gender. All values must be valid (weight > 0, height > 0, age between 2-18).

5. Frequently Asked Questions (FAQ)

Q1: What do BMI percentiles mean for children?
A: Underweight (<5th percentile), Healthy weight (5th to <85th percentile), Overweight (85th to <95th percentile), Obese (≥95th percentile).

Q2: Why is BMI interpreted differently for children?
A: Children's body composition varies as they grow, and BMI changes with age. Percentiles account for these normal growth patterns.

Q3: How accurate is BMI for children?
A: BMI is a good screening tool but not a diagnostic measure. Some muscular children may have high BMI without excess fat.

Q4: How often should children's BMI be checked?
A: NHS recommends annual BMI checks for children as part of routine health assessments.

Q5: Where can I plot my child's BMI percentile?
A: NHS provides growth charts for plotting BMI percentiles based on age and gender.