1. What is BMI for Boys?

BMI (Body Mass Index) is a measure that uses height and weight to assess whether a child's weight is appropriate for their height. For children and teens, BMI is age- and sex-specific and is often referred to as BMI-for-age.

2. How Does the Calculator Work?

The calculator uses the standard BMI formula:

Where:

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

Explanation: The result is then compared to male-specific BMI-for-age growth charts to determine the percentile ranking.

3. Importance of BMI Calculation

Details: BMI screening for children can identify potential weight problems, but it's not a diagnostic tool. A healthcare professional should perform further assessments to determine if excess fat is a problem.

4. Using the Calculator

Tips: Enter weight in kilograms, height in meters, and age in years. For accurate results, measurements should be taken with minimal clothing and no shoes.

5. Frequently Asked Questions (FAQ)

Q1: What are the NHS BMI percentile categories for boys?
A: Underweight (below 5th percentile), Healthy weight (5th to 85th percentile), Overweight (85th to 95th percentile), Obese (95th percentile or above).

Q2: Why use age-specific BMI for children?
A: Children's body composition changes as they grow, so BMI must be interpreted relative to other children of the same age and sex.

Q3: What if my child's BMI is high?
A: Consult your GP or health visitor who can assess growth patterns over time and consider other factors like muscle mass.

Q4: How often should BMI be checked in children?
A: The NHS measures children's height and weight at school entry (age 4-5) and in Year 6 (age 10-11) as part of the NCMP programme.

Q5: Are there limitations to BMI for children?
A: BMI doesn't distinguish between fat and muscle mass, so athletic children may have higher BMIs without excess fat.