BMI Calculator
Calculate your Body Mass Index (BMI) in metric or imperial units, see the WHO adult category and the weight range that matches the standard reference range. Everything is calculated in your browser.
Your Details
Health note: BMI is a screening estimate for adults, not a diagnosis. It does not directly measure body fat and may not suit everyone -- for example athletes, older adults or pregnant people. Talk to a qualified healthcare professional about what a healthy weight means for you.
Results
Your BMI
Category (WHO adult reference):
Weight range for BMI 18.5–24.9 at your height
Your weight compared with that range
| BMI | WHO adult category |
|---|---|
| Below 18.5 | Underweight |
| 18.5 – 24.9 | Healthy weight |
| 25.0 – 29.9 | Overweight |
| 30.0 – 34.9 | Obesity class I |
| 35.0 – 39.9 | Obesity class II |
| 40.0 and above | Obesity class III |
Some Asian and South Asian guidance, including India's, uses lower cut-offs (around 23 for overweight and 25 for obesity). BMI does not directly measure body fat, and doesn't account for muscle mass, body shape, age, sex or ethnicity.
How this calculator works
BMI = weight in kilograms ÷ (height in metres)². For imperial units, your feet/inches and pounds are converted to centimetres and kilograms first. The result is shown to one decimal place and matched to the World Health Organization adult categories. The reference weight range is the weight that would give a BMI between 18.5 and 24.9 at your height. BMI is a population-level screening tool: it is useful for spotting trends but cannot tell muscle from fat or say anything about your individual health on its own.
Is BMI an accurate measure of health?
No single number is. BMI is a quick screening measure based only on height and weight. It does not measure body fat directly, and it does not distinguish muscle from fat, account for where fat is stored, or consider age, sex, ethnicity, fitness or medical history. A muscular person can have a high BMI with little body fat, while someone with a “normal” BMI can still carry excess abdominal fat.
What are the BMI categories?
For adults, the World Health Organization uses: under 18.5 underweight, 18.5 to 24.9 healthy weight, 25 to 29.9 overweight, and 30 or more obesity (class I 30-34.9, class II 35-39.9, class III 40+). Some guidance for South Asian and other Asian populations, including India, uses lower cut-offs (for example 23 for overweight and 25 for obesity) because health risks can rise at lower BMI.
Is my data stored or shared?
No. Your height and weight are used only in your browser to calculate the result. Nothing is sent to our servers, stored, or included in analytics.
Can children use this calculator?
No. This calculator is for adults aged 18 and over. BMI for children and teenagers is interpreted with age- and sex-specific growth charts, which a doctor or health professional can explain.
Disclaimer: This calculator is for general information only and is not medical advice, diagnosis or treatment. It is intended for adults aged 18 and over. See our Disclaimer and Terms of Use for more detail.