Calculate your Body Mass Index instantly. Supports both metric and imperial units. Find your healthy weight range for your height.
Your measurements
Enter your height and weight to calculate your BMI and see which category you fall into.
Enter your height in centimetres or feet/inches, and weight in kilograms or pounds. The calculator handles both measurement systems without any manual conversion.
Your BMI is automatically categorized as Underweight, Normal, Overweight, or Obese (Class I, II, III) based on WHO and NIH standard BMI ranges.
See the ideal weight range for your height — the weight corridor that corresponds to a normal BMI (18.5–24.9), helping you set realistic health goals.
BMI (Body Mass Index) is a screening tool that estimates body fat based on your height and weight. Formula: BMI = weight(kg) ÷ height(m)². It is widely used by healthcare professionals as a quick, low-cost initial assessment — though it does not directly measure body fat percentage or account for muscle mass.
For adults, the WHO classifies BMI as: Underweight (below 18.5), Normal weight (18.5–24.9), Overweight (25.0–29.9), Obese Class I (30.0–34.9), Obese Class II (35.0–39.9), and Obese Class III (40 and above). Asian populations may use lower thresholds — normal below 23.0 — due to different body composition risks.
BMI for children and teens (ages 2–19) is calculated the same way but interpreted using age- and sex-specific percentiles from growth charts, not the fixed adult ranges. This tool uses adult classification standards — consult a paediatrician for children's BMI assessment.