⚖️ Free BMI Calculator

Calculate your Body Mass Index using WHO standards. Get your category, healthy weight range, health risk level and personalised tips. Metric and imperial supported.

Calculate Your BMI

Enter your height and weight below. Results are instant and based on WHO BMI classifications.

Calculating using WHO standards…
UnderweightNormalOverweightObese
Health Risk Level

WHO BMI Categories — Reference Guide

The World Health Organisation classifies Body Mass Index into four main categories for adults:

UnderweightBelow 18.5
Normal weight18.5 to 24.9
Overweight25.0 to 29.9
Obese30.0 and above

Limitations of BMI

BMI is a useful screening tool but has important limitations. It does not account for muscle mass, bone density, age, sex or ethnicity. A highly muscular person may have a high BMI without excess body fat. BMI should be used alongside other health measures such as waist circumference and blood pressure for a complete picture of health.

How to Reach and Maintain a Healthy Weight

Balanced Diet

Focus on whole foods — vegetables, fruits, whole grains, lean proteins and healthy fats. Limit processed foods, added sugar and excessive sodium. For Muslims following a halal diet, excellent protein sources include chicken, fish, eggs, lentils and chickpeas. Use our Halal Checker to verify ingredients in packaged foods.

Regular Physical Activity

The NHS and WHO recommend at least 150 minutes of moderate intensity activity per week for adults. This includes brisk walking, cycling, swimming or any activity that raises your heart rate. Strength training twice per week helps maintain and build muscle mass.

Track Your Calories

Understanding how many calories you consume helps you make better dietary choices. Use our free photo calorie scanner to get instant nutrition data for any meal.

Frequently Asked Questions

⚠️ Disclaimer: BMI is a general screening tool only. It does not constitute medical advice. Always consult a qualified healthcare professional for personalised health and weight management guidance.