BMI Calculator NHS
Calculate Body Mass Index (BMI) and check adult weight category. Includes an approximate child BMI centile helper (see note).
Calculator
Welcome to our BMI Calculator NHS, a simple and accurate way to check your Body Mass Index (BMI) and find out if you’re at a healthy weight. Whether you’re tracking weight loss, assessing health risks, or checking your child’s growth pattern, this tool helps you understand your health status based on your weight in kilograms and height in metres.
What is BMI (Body Mass Index)?
Body Mass Index (BMI) is a health indicator that measures your body fat based on your height and weight. It helps you identify if you are underweight, a healthy weight, overweight, or obese. While BMI doesn’t directly measure muscle mass or bone density, it provides a reliable estimate of your overall health.
How to Use the BMI Calculator NHS
- Choose your Measurement System – Metric (kg, cm).
- Enter your weight in kilograms.
- Enter your height in metres using a tape measure.
- Select your age group – Adult or Child.
- Add your gender, ethnic background (optional), and activity level.
- Click Calculate BMI to see your results instantly.
Adult and Child BMI Calculator
- Adult BMI Calculator: Helps assess health risks like heart disease, type 2 diabetes, and high blood pressure.
- Child BMI Calculator: Calculates the child’s BMI centile using growth charts to see if your child is a healthy weight or at risk of overweight children issues.
Ethnic Background and Health Risks
Different ethnic groups may face varying health risks at the same BMI.
- South Asian men, Middle Eastern, and Black African adults may be at higher risk of type 2 diabetes and heart disease even with lower BMI scores.
- Use the NHS Body Mass Calculator or consult your GP surgery for a personalized health assessment.
Why BMI Matters
Your BMI can indicate the likelihood of developing chronic conditions like heart and circulatory diseases, high cholesterol levels, type 2 diabetes, blood pressure problems, and fluid retention or other health concerns. Monitoring your waist size, tummy fat, and waist-to-height ratio can give more insight into your health risk.
Maintaining a Healthy BMI
A balanced diet, regular physical activity, and good workout routines help you stay within your target range.
Follow these healthy lifestyle habits:
- Choose balanced diets with proper portion sizes.
- Join a healthy lifestyle programme if you need help with weight loss.
- Track calorie allowance using tools like a Calorie Calculator or Basal Metabolic Rate (BMR) Calculator.
- Check blood sugar tests and cholesterol levels regularly.
Waist Measurement & Health Indicators
Even with a normal BMI, having excess waist circumference or tummy fat increases health risks.
Use a tape measure to check your waist:
- Men: Keep below 94 cm (37 in)
- Women: Keep below 80 cm (31.5 in)
Children and Teenagers
For children and teenagers, BMI results are interpreted using growth charts to determine BMI centile. This helps track child’s growth and identify early health issues.
- Child’s BMI centile: Shows how your child compares to others of the same age group and gender.
- Always consult a GP if your child’s BMI is high or low.
Special Considerations
BMI results may differ for Older adults, pregnant or lactating women, or those with eating disorders. Factors like bone density and muscle mass can also affect accuracy. Always consult a doctor for detailed health advice.
Other Health Tools You Can Use
For a complete health assessment, try other online calculators like a Calorie Calculator, Basal Metabolic Rate (BMR) Calculator, or Glucose Ketone Index Calculator. These tools complement your BMI results to help maintain your healthy lifestyle.
Health Topics and Support
For medical advice, visit the NHS website, use the symptom checker, or reach out to your GP surgery. Health information is provided for awareness by trusted sources such as Core Prescribing Solutions, Patient Informatics, and Frontline workers.
Technical Help & Embed Code
Need to embed this BMI Calculator on your website? Contact our technical help team for the embed code and improve your users’ experience with reliable health tools.
Last Modified & Updates
This calculator and guide are regularly updated to reflect the latest NHS guidelines and health topics related to BMI, waist measurement, and chronic conditions.
Final Words
Your BMI is more than just a number—it’s a health indicator that helps you understand your body fat, fitness, and overall well-being. Start today with our easy-to-use adult BMI calculator or child BMI calculator and take your first step toward a healthier, balanced lifestyle.