BMI Calculator
Check your body mass index and see where it falls on the healthy range.
Quick answer
Body mass index (BMI) is weight in kilograms divided by height in metres squared (or, in US units, 703 × pounds ÷ inches²). Standard adult ranges are: under 18.5 underweight, 18.5–24.9 healthy, 25–29.9 overweight, and 30 or more obese. BMI is a population screen and doesn't distinguish muscle from fat.
Your BMI
22.9
Healthy range
Healthy weight
57–76 kg
Underweight
15–18.5
Healthy
18.5–25
Overweight
25–30
Obese
30+
How BMI is calculated
Body mass index divides weight by height squared — kg/m² in metric, or (lb ÷ in²) × 703 in imperial units. The World Health Organization ranges are: Underweight (0–18.5), Healthy (18.5–25), Overweight (25–30), Obese (30+).
What BMI can and can't tell you
BMI is a quick population-level screen, not a diagnosis. It doesn't distinguish muscle from fat — athletes often read "overweight" while carrying little fat — and it doesn't capture where fat is stored, which matters more for health risk. Waist circumference, body-fat percentage, and a clinician's assessment give a fuller picture.
Frequently asked questions
- How does the BMI Calculator work?
- Body mass index (BMI) is weight in kilograms divided by height in metres squared (or, in US units, 703 × pounds ÷ inches²). Standard adult ranges are: under 18.5 underweight, 18.5–24.9 healthy, 25–29.9 overweight, and 30 or more obese. BMI is a population screen and doesn't distinguish muscle from fat.
- Is the BMI Calculator free to use?
- Yes. The BMI Calculator is completely free, runs entirely in your browser, and requires no account or sign-up. Your inputs never leave your device.
Sources & methodology
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