BMI Calculator
Enter your weight and height to calculate your body mass index.
- BMI
- 22.9
- Category
- Normal weight
22.9
UnderweightNormal weightOverweightObesity
How BMI is calculated
Body mass index relates your weight to your height squared. It's a general estimate, not a medical diagnosis.
BMI = weight (kg) ÷ height (m)²
The World Health Organization has used BMI as a population screening tool since the 1990s for its simplicity, but it was originally designed in the 19th century for statistical studies, not to assess an individual's health.
Worked example
A person weighing 70 kg at 1.75 m has a BMI of 70 ÷ 1.75² = 22.9, within the normal weight range. A person weighing 90 kg at the same height would have a BMI of 90 ÷ 1.75² = 29.4, at the edge of overweight.
Frequently asked questions
- What is BMI?
- Body mass index (BMI) is an indicator that relates weight to height to estimate whether a person is within a healthy weight range.
- What are the BMI ranges?
- Below 18.5: underweight. 18.5 to 24.9: normal weight. 25 to 29.9: overweight. 30 or above: obesity.
- Is BMI reliable for everyone?
- Not always. It doesn't distinguish between muscle mass and fat, so it can be inaccurate for athletes, pregnant women, older adults, or children.
- Does BMI replace a medical checkup?
- No. It's only a general guideline. For a proper health assessment, consult a healthcare professional.
- Why can a bodybuilder have a high BMI without being overweight?
- Because muscle weighs more than fat for the same volume; BMI doesn't distinguish between the two tissues, so a very muscular person can be classified as overweight or obese without actually being so.
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