Calculate your Body Mass Index and find your healthy weight range.
Body Mass Index (BMI) is a numerical value derived from your weight and height, used as a screening tool for weight categories. The formula is BMI = weight (kg) / height (m)2. For imperial units: BMI = 703 × weight (lbs) / height (in)2.
Standard WHO categories: Underweight <18.5, Normal weight 18.5–24.9, Overweight 25–29.9, Obese ≥30. BMI is widely used because it requires no equipment and correlates reasonably well with body fat at the population level. However, it has known limitations: it cannot distinguish muscle from fat (athletes often show "overweight" BMI), doesn't account for fat distribution, and has different risk thresholds for different ethnicities (Asian populations face increased health risk at BMI >23). BMI is best used as one data point among many — including waist circumference, blood pressure, and blood markers — when assessing overall health.
According to the WHO, a BMI between 18.5 and 24.9 is considered a normal healthy weight. Below 18.5 is underweight, 25–29.9 is overweight, and 30 or above is classified as obese. For people of Asian descent, a threshold of 23 is used for increased health risk.
BMI is a useful population-level screening tool but has significant individual limitations. It cannot distinguish muscle from fat, so muscular athletes often appear 'overweight'. It also ignores fat distribution — a pot belly carries more risk than the same fat distributed evenly.
For children and adolescents (2–19 years), BMI must be interpreted using age- and sex-specific percentile charts, not the adult thresholds. A child's BMI is compared against peers of the same age and gender, not against fixed cutoffs.
BMI decreases by reducing body fat, which requires a sustained calorie deficit — consuming fewer calories than you burn. Combining calorie control with strength training is most effective, as it preserves or builds muscle while reducing fat mass.