Enter your height and weight to instantly calculate your Body Mass Index and see what it means for your health.
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⚠️ Screening tool only. BMI is not a medical diagnosis. It does not account for muscle mass, bone density, or body composition. Consult a healthcare provider for personalized advice.
Body Mass Index (BMI) is a measurement calculated from your height and weight that gives a general indication of whether your weight is in a healthy range. It is widely used by healthcare professionals as a quick screening tool, though it has limitations and should not be used as a sole measure of health.
This calculator supports both metric (kg/cm) and imperial (lbs/ft/in) units and also shows your healthy weight range — the weight range that would put you in the normal BMI category for your height.
BMI is calculated as weight (kg) ÷ height² (m²). For imperial units, the formula is adjusted accordingly. The WHO defines normal weight as a BMI between 18.5 and 24.9.
BMI Calculator FAQ
A healthy BMI is between 18.5 and 24.9 according to the World Health Organization. Below 18.5 is underweight, 25–29.9 is overweight, and 30 or above is classified as obese. These categories apply to most adults aged 18–65.
BMI is a useful screening tool but has limitations. It does not account for muscle mass, bone density, or fat distribution. Athletes often have a high BMI due to muscle, while some people with a normal BMI may have unhealthy levels of body fat. Use BMI as one indicator alongside other health measures.
BMI = weight (kg) ÷ height² (m²). For example, 70kg ÷ (1.75 × 1.75) = 22.9. For imperial: BMI = (weight in lbs × 703) ÷ height in inches². Our calculator handles both formulas automatically.
Healthy weight corresponds to a BMI of 18.5–24.9. For someone 175cm (5'9") tall, that is approximately 56kg to 76kg (124–168 lbs). Our calculator shows your healthy weight range after you calculate your BMI.
Standard BMI categories apply to adults aged 18 and over. For children and teenagers, BMI is calculated the same way but interpreted using age and sex-specific percentiles rather than fixed cutoff values. Consult a paediatrician for children's BMI assessment.
Yes. Some people have a normal BMI but carry excess fat around the abdomen (central obesity), which is associated with higher health risks. Conversely, some people with a slightly elevated BMI (e.g. 25–27) who are active and eat well may be in good health. BMI is just one screening tool.