1. What is the NHS Children's BMI Calculator?

The NHS Children's BMI Calculator uses the standard BMI formula adjusted for age and gender percentiles to assess whether a child's weight is healthy for their height and age.

2. How Does the Calculator Work?

The calculator uses the standard BMI formula:

Where:

• \( weight \) — Child's weight in kilograms
• \( height \) — Child's height in meters

Explanation: The result is then compared to UK growth charts to determine the child's percentile for their age and gender.

3. Importance of BMI Calculation for Children

Details: Tracking BMI in children helps identify potential weight problems early. Unlike adults, children's BMI must be interpreted relative to other children of the same age and sex.

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 with minimal clothing.

5. Frequently Asked Questions (FAQ)

Q1: Why is children's BMI different from adults?
A: Children's body composition changes as they grow, so their BMI must be compared against growth charts for their specific age and gender.

Q2: What are the percentile categories?
A: Underweight (<5th), Healthy weight (5th-85th), Overweight (85th-95th), Obese (≥95th percentile).

Q3: When should I be concerned about my child's BMI?
A: If your child is below the 5th or above the 85th percentile, consult your GP or health visitor.

Q4: Are there limitations to BMI for children?
A: BMI doesn't distinguish between muscle and fat, so athletic children may appear overweight. Always consider individual circumstances.

Q5: How often should my child's BMI be checked?
A: Routine measurements are typically done at school entry (age 4-5) and in year 6 (age 10-11) as part of the NCMP programme.