MedDroidBMI calculator
Built by MedDroid · formulas from WHO
Free · no sign-up · runs in your browserWork out your body mass index (BMI) in metric or imperial units. You get the WHO category and, on a second line, the lower cut-offs often used for Asian and South Asian adults.
BMI calculator
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Your result
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How it works
BMI = weight in kilograms ÷ (height in metres × height in metres). In imperial units, the calculator first converts pounds to kilograms (1 lb = 0.4536 kg) and feet and inches to metres (1 in = 2.54 cm).
Example: 70 kg and 175 cm gives 70 ÷ (1.75 × 1.75) = 22.9.
The first line uses the World Health Organization (WHO) adult categories: below 18.5 underweight, 18.5 to 24.9 healthy, 25 to 29.9 overweight, 30 or more obesity.
The second line uses the public-health action points from the WHO expert consultation on BMI in Asian populations (The Lancet, 2004): 23 for increased risk and 27.5 for high risk. Some Indian guidelines use similar lower cut-offs.
Related pages
Not a diagnosis. This tool gives a general estimate from a standard published formula. It is not a diagnosis and does not replace a check-up by a qualified doctor. If you feel very unwell, call your local emergency number (India: 108 or 112).
Frequently asked questions
What is a normal BMI?
For adults, WHO calls a BMI of 18.5 to 24.9 a healthy weight. For many Asian and South Asian adults, risk of diabetes and heart disease starts to rise from about 23.
Why are the Asian BMI cut-offs lower?
Studies found that many Asian people have more body fat and a higher risk of type 2 diabetes and heart disease at the same BMI as European people. A WHO expert consultation therefore suggested extra action points at 23 and 27.5.
Is BMI accurate for athletes or older people?
Not always. Muscle weighs more than fat, so muscular people can have a high BMI without extra fat. Older adults can have a normal BMI with less muscle and more fat. Waist size and a doctor's check add useful detail.
Can I use this BMI calculator for my child?
No. Children and teenagers need BMI-for-age charts, because healthy BMI changes as they grow. Ask your child's doctor to plot it on a growth chart.