BMI Calculator – Body Mass Index with Healthy Weight Range

Body Mass Index (BMI) is a simple ratio of weight to height that provides a quick screening signal for weight-related health risk. It's not a diagnostic tool, and it has real limitations — it doesn't distinguish between muscle and fat, and it can misclassify athletes and older adults. But for the general population, it's a reasonable starting point for understanding where your weight falls relative to health guidelines. This calculator gives you your BMI, the standard WHO category (Underweight, Normal, Overweight, Obese Classes I–III), your healthy weight range for your specific height, and how much you'd need to gain or lose to reach that range — in either imperial (lbs/ft) or metric (kg/cm) units. For context, the Centers for Disease Control considers BMI 18.5–24.9 the "normal" range for adults. BMI above 30 is associated with increased risk of type 2 diabetes, cardiovascular disease, and certain cancers — but absolute risk depends on many factors beyond BMI alone.