Free BMI calculator for men and women: get your Body Mass Index, WHO health category and healthy weight range instantly in metric or imperial units.
Body Mass Index (BMI) is a quick screening number that relates your weight to your height. It is used worldwide by doctors and health organizations to flag weight categories — underweight, normal, overweight, or obese — and to track changes over time.
Enter your height and weight in metric or imperial units. The result shows your BMI value, its category, and the healthy weight range for your height. BMI is a starting point, not a diagnosis: muscle mass, age, and body composition matter too, so use it together with other health indicators.
A BMI between 18.5 and 24.9 is considered healthy. Below 18.5 is underweight, 25-29.9 is overweight, and 30+ is obese.
BMI may overestimate body fat for athletes and muscular individuals because muscle weighs more than fat. Waist circumference and body fat percentage measurements can provide a more complete health assessment.
BMI does not distinguish between muscle and fat, does not account for fat distribution, and may not be accurate for elderly individuals, pregnant women, or children. It is a screening tool, not a diagnostic one.
BMI only compares weight and height and cannot tell how much of that weight is muscle or fat. Body fat percentage measures fat directly; two people with the same BMI can have very different body fat levels. For a fuller picture, combine BMI with waist measurement or body fat estimation.
No. For children and teens, BMI is compared against age- and sex-specific growth charts (percentiles) rather than fixed adult cutoffs, because body composition changes as they grow. This calculator is intended for adults.
Focus on sustainable habits: a moderate calorie deficit, regular strength and cardio training, and enough protein and sleep. Small consistent changes over weeks and months move your BMI more reliably than crash diets.