Body mass index with health ranges and visual meter.
Body Mass Index (BMI) is a simple screening measurement that relates your weight to your height, giving a quick indication of whether you fall into an underweight, normal, overweight, or obese range according to World Health Organization guidelines. It's widely used by doctors as a starting point for a conversation, not a complete diagnosis.
This calculator supports both metric (kg/cm) and imperial (lb/inches) units, so you can use whichever measurement system you're comfortable with.
Is BMI an accurate measure of health?
BMI is a useful general screening tool but has known limitations — it doesn't distinguish between muscle and fat, so athletes and very muscular individuals can show a higher BMI without carrying excess body fat. It also doesn't account for age, sex, or body composition differences.
What BMI range is considered "normal"?
The standard WHO ranges are: under 18.5 (underweight), 18.5–24.9 (normal weight), 25–29.9 (overweight), and 30+ (obese). These are general population guidelines, not individual medical advice.
Should I make health decisions based on BMI alone?
No — BMI is a starting point, not a diagnosis. If you have concerns about your weight or health, talk to a doctor who can consider your full picture.