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BMI Calculator

Calculate your Body Mass Index in metric or imperial units, see your category and healthy weight range, and understand what BMI can and can't tell you.

2026 rates · Last reviewed: 2026

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What BMI measures

Body Mass Index compares your weight to your height with a simple formula (weight in kg divided by height in metres squared). It's a quick screening tool that works reasonably well across large populations — but it's a starting point, not a diagnosis.

The standard categories

BMICategory
Below 18.5Underweight
18.5 – 24.9Healthy weight
25.0 – 29.9Overweight
30.0 +Obesity range

What BMI can't tell you

BMI doesn't distinguish muscle from fat, or show where fat is stored. A muscular athlete may read as "overweight" while being very lean. It also doesn't account for age, sex, or ethnic differences in body composition.

For the full picture of what your number means and what else to consider, read what does my BMI mean. Pairing BMI with a waist measurement and basic health markers gives far more insight than the number alone.

Please remember

This tool is for general information and isn't medical advice. It isn't appropriate for children, pregnant people, or athletes. If you have any concern about your weight or health, talk with a doctor who can consider your whole situation.

This calculator provides estimates for general information only and is not medical advice. See our disclaimer.