Child BMI Calculator NHS

BMI Formula:

\[ BMI = \frac{weight\ (kg)}{height^2\ (m)} \]

Weight:

Height:

meters

Age:

years

Gender:

BMI Result:

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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:

\[ BMI = \frac{weight\ (kg)}{height^2\ (m)} \]

Where:

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

Note: For children, the raw BMI number must be plotted on a gender-specific BMI-for-age growth chart to determine the percentile.

3. Importance of BMI Calculation

Details: BMI is a screening tool that can indicate whether a child is underweight, healthy weight, overweight, or obese. However, it's not a diagnostic tool and should be followed up with additional assessments.

4. Using the Calculator

Tips: Enter weight in kilograms, 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: What is a healthy BMI for children?
A: Unlike adults, children's BMI is interpreted using percentile charts. Generally:

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

Q2: Why is BMI different for children?
A: Children's body composition varies with age and between boys and girls, so their BMI needs to be compared against growth charts specific to their age and sex.

Q3: When should I be concerned about my child's BMI?
A: Consult a healthcare provider if your child's BMI is below the 5th percentile or above the 85th percentile, or if there's been a sudden change in their BMI percentile.

Q4: Are there limitations to BMI for children?
A: Yes. BMI doesn't distinguish between muscle and fat, so athletic children may have high BMIs without excess fat. It's always best to consult a healthcare professional for interpretation.

Q5: Where can I find NHS BMI percentile charts?
A: NHS growth charts are available through healthcare providers and on the official NHS website, showing BMI percentiles for boys and girls from age 2-18.