Your BMI
24.5
Healthy
BMI Categories
What is BMI?
Body Mass Index is a simple calculation using height and weight. While not perfect (it does not account for muscle mass), it is a widely used screening tool for weight categories. For a more complete picture, consider measuring body fat percentage or waist circumference.
About BMI Calculator
Body Mass Index (BMI) is a simple screening tool that uses your height and weight to estimate whether you fall into an underweight, healthy weight, overweight, or obese category. Developed by Belgian mathematician Adolphe Quetelet in the 1830s, BMI remains one of the most widely used population-level health indicators despite its well-known limitations.
The formula divides your weight in kilograms by the square of your height in metres. A BMI between 18.5 and 24.9 is generally considered healthy for most adults, though these ranges were developed primarily from studies of European populations and may not apply equally across all ethnicities. For example, health risks associated with excess weight may begin at a lower BMI for people of South Asian descent.
It is important to understand what BMI cannot tell you. It does not distinguish between muscle mass and fat mass, meaning athletes and bodybuilders often register as overweight despite having low body fat. It does not account for where fat is stored — visceral fat around organs is far more dangerous than subcutaneous fat under the skin. It also ignores age, sex, and bone density.
BMI is best used as a starting point for health conversations, not a definitive diagnosis. If your BMI falls outside the healthy range, consider supplementing with waist circumference measurements, body fat percentage tests, or a conversation with your GP about your overall health picture.
How to Use
- Enter your height in either centimetres or feet and inches
- Enter your weight in kilograms or stones and pounds
- View your BMI score and the category it falls into
- Read the guidance notes to understand what the result means for your situation
Why This Matters
While BMI has limitations, it remains a useful first-pass health indicator recommended by the NHS and WHO. Tracking your BMI over time can help you spot gradual weight changes before they become health issues. Combined with other measurements like waist circumference and body fat percentage, it gives you a more complete picture of your physical health without needing expensive medical equipment.