BMI Calculator NHS
Check Your Body Mass Index with the Official NHS Tool
Our BMI Calculator NHS helps you determine if you’re at a healthy weight. Based on trusted NHS guidelines, this tool provides personalized health advice and next steps based on your results.
Fast & Accurate
Results in seconds with personalized advice
NHS Trusted
Based on official NHS health guidelines
For Everyone
Adult and child BMI calculators available
Calculate Your BMI
Your BMI Results
BMI Categories
BMI Calculator NHS Features
NHS Guidelines
Our BMI calculator uses official NHS guidelines to provide the most accurate health assessments and personalized recommendations.
Adult & Child BMI
Separate calculators for adults and children with age and gender-specific assessments for the most appropriate guidance.
Detailed Results
Get comprehensive results including your BMI category, health risk assessment, and personalized recommendations.
Ethnicity Factors
Special consideration for people from Asian, Black, and other ethnic backgrounds who may have different BMI risk thresholds.
Metric & Imperial Units
Easily toggle between metric (kg/cm) and imperial (stones/pounds/feet/inches) measurement systems to suit your preference.
Advanced Tools
Connect with our other health tools including BMI History Tracker, Body Composition Calculator, and Personalized Health Plans.
Our BMI Health Tools
Explore our comprehensive suite of BMI and health assessment tools designed to help you monitor, understand, and improve your overall wellbeing.
BMI History Tracker
Track your BMI changes over time with visual charts and progress monitoring to help you stay motivated and reach your health goals.
Body Composition Calculator
Go beyond BMI with detailed body composition analysis including body fat percentage, lean mass, and metabolic rate calculations.
BMI Comparison Tool
Compare your BMI with national averages and different demographic groups to understand where you stand relative to the population.
Calorie Calculator
Calculate your daily calorie needs based on your BMI, activity level, and weight goals with personalized meal planning guidance.
Health Risk Assessment
Evaluate your health risks based on BMI and other factors to understand potential health concerns and receive targeted recommendations.
Baby Weight Percentile Calculator
Check your baby’s weight percentile according to UK standards with our specialized calculator for infants and young children.
Frequently Asked Questions
What is BMI and how is it calculated?
Body Mass Index (BMI) is a numerical value derived from your weight and height. It provides a simple measure to assess whether you are at a healthy weight. The formula is: BMI = Weight (kg) ÷ Height² (m²). Our BMI Calculator NHS automatically performs this calculation for you.
How accurate is BMI as a health indicator?
BMI is a useful screening tool for populations, but it has limitations. It doesn’t distinguish between muscle and fat mass or account for where fat is stored in the body. For a comprehensive health assessment, BMI should be considered alongside other factors like waist circumference, lifestyle, and family history.
Why is my child’s BMI calculated differently?
Children’s bodies change as they grow and develop, and the amount of body fat differs between boys and girls. For children and teens aged 2-17, BMI is calculated using age and sex-specific charts, resulting in a centile that shows how your child compares to others of the same age and sex.
How often should I check my BMI?
For most adults, checking BMI once or twice a year is sufficient unless you’re actively trying to lose weight or have been advised by a healthcare professional to monitor it more frequently. Use our BMI History Tracker to monitor changes over time.
Why does ethnicity matter for BMI?
Research shows that people from Asian, Black African, African-Caribbean, and Middle Eastern backgrounds may have increased health risks at lower BMI values than people from White backgrounds. For Asian populations specifically, health risks may start at a BMI as low as 23, rather than 25 for the general population.
Take Control of Your Health Today
Start your journey to better health by calculating your BMI and exploring our comprehensive suite of health assessment tools.