How is BMI calculated?
BMI = weight in kilograms ÷ (height in metres)². For pounds and inches: BMI = 703 × lb ÷ in². A person 170 cm tall weighing 65 kg has a BMI of 22.5.
BMI categories
The World Health Organization uses: under 18.5 underweight, 18.5–24.9 normal, 25–29.9 overweight, 30 and above obese. Because health risks start at lower BMI in many Asian populations, some countries use lower cutoffs. Taiwan’s Health Promotion Administration uses 24 for overweight and 27 for obesity, and Japan’s obesity society classes 25 and above as obese. Pick the standard that fits you above.
Limits of BMI
BMI does not tell muscle from fat, so athletes may read as overweight. It is meant for adults 18 and over; children and teens use age- and sex-specific percentile charts. Treat it as a quick screening number and talk to a doctor about your own health.
Is anything sent to a server?
No. Every calculation runs in your browser. Nothing you type here is uploaded or stored anywhere else.