Calculate your Body Mass Index instantly. Get your BMI value and WHO health classification.
Choose metric (kg/cm) or imperial (lb/in), enter your weight and height, then click “Calculate BMI”. The result shows your BMI value plus the WHO category — underweight, normal, overweight or obese — so you can see where you stand at a glance.
BMI is a screening tool, not a diagnosis. Athletes with high muscle mass often score high, and older adults may be healthy at a slightly higher BMI. Use it to track long-term trends, and always combine it with waist circumference or a doctor’s advice for a full picture.
For children and teenagers, BMI is interpreted using age- and sex-specific percentiles, not the adult ranges shown here. If your BMI falls outside the normal range, focus on sustainable habits - balanced meals, regular movement and enough sleep - rather than crash dieting.
Track your BMI monthly rather than daily - daily fluctuations from water weight are normal and misleading. Pair the number with simple measurements like waist size to see a fuller picture, and consult a healthcare professional if you plan major changes.
Body Mass Index (BMI) is a screening tool that estimates body fat based on height and weight. It's calculated by dividing weight in kg by height in meters squared. While not a perfect health metric, it's a useful starting point for understanding weight-related health risks.
Limitations: BMI doesn't account for muscle mass, bone density, or fat distribution. Athletes and older adults should use it as a rough guide, not a diagnosis.
Body Mass Index (BMI) is a screening tool that estimates body fat based on height and weight. It's calculated as weight (kg) divided by height squared (m²).
BMI may overestimate body fat in athletes with high muscle mass and underestimate it in older adults with low muscle mass. Use it as a general guide.
A BMI between 18.5 and 24.9 is considered the healthy range by WHO standards. Below 18.5 is underweight, 25–29.9 is overweight, and 30+ is obese.
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BMI = weight (kg) / height squared (m). A person of 1.75 m and 70 kg has a BMI of 70 / 3.0625 = 22.9, which falls in the healthy range. The standard categories are: below 18.5 underweight, 18.5-24.9 healthy, 25-29.9 overweight, 30+ obese.
BMI is a population-level screening tool, not a diagnosis. Athletes with high muscle mass often show 'overweight' BMIs while being lean; older adults may be classified healthy despite low muscle (sarcopenia); children and pregnant women need age/sex-specific charts. Use waist circumference and body-fat percentage alongside BMI, and consult a doctor for health decisions.
Note: BMI category boundaries are the same worldwide per WHO, but some countries (e.g. China) use a lower overweight threshold of 24 for public-health screening.