BMI Calculator
Free BMI calculator for adults. Enter weight in kg and height in cm to get your BMI in kg/m² with its category under WHO and WHO Asian cut-offs, privately.
What is the BMI Calculator?
Body mass index, or BMI, compares your weight with your height and is one of the most common screening numbers used in health check-ups. This BMI calculator asks for two values, your weight in kilograms and your height in centimetres, and returns your BMI in kg/m². It uses the standard formula of weight divided by height in metres squared, so the number matches what a doctor or fitness app would compute.
Below the number, the tool shows your category twice: by the international WHO cut-offs and by the WHO cut-offs for Asian populations, which many Indian health bodies follow because health risks start at a lower BMI. Under WHO, 18.5–24.9 is healthy, 25–29.9 overweight and 30 or more obese; under the Asian cut-offs, 18.5–22.9 is healthy, 23–27.4 overweight and 27.5 or more obese. BMI is an adult screening measure only. It does not separate muscle from fat and is not suitable for children or during pregnancy.
How to use the BMI Calculator
- Enter your weight in kilograms in the Weight (kg) field, for example 68.5. Values from 2 to 500 are accepted.
- Enter your height in centimetres in the Height (cm) field, from 50 to 272. For 5 ft 7 in, use about 170.
- Press Calculate to see your BMI in kg/m².
- Read the WHO and WHO Asian categories under the result, along with the reminder that this is a screening measure, not a diagnosis.
- Copy the value to share with your doctor or log it, or press Reset to try new numbers.
Features
- Standard formula: weight in kg divided by height in metres squared
- Metric inputs in kilograms and centimetres
- Accepts decimal weight and height
- Category by WHO cut-offs and by WHO Asian cut-offs
- Range checks: weight 2–500 kg and height 50–272 cm
Why use this bmi calculator
- Know your BMI before a check-up
- Track changes over weeks with consistent inputs
- No account and no data sent anywhere
- Works on a phone in seconds
Formula used
BMI = body mass kg / (height metres)².
Examples
Healthy under both sets of cut-offs
Input: Weight (kg): 70, Height (cm): 175
Result: 22.8571 kg/m² Category (WHO): Healthy weight Category (WHO Asian cut-offs): Healthy weight Adult screening measure, not a diagnosis; unsuitable for children or pregnancy. About 22.9, worked out as 70 divided by 1.75 squared.
Where WHO and Asian cut-offs differ
Input: Weight (kg): 72, Height (cm): 170
Result: 24.9135 kg/m² Category (WHO): Healthy weight Category (WHO Asian cut-offs): Overweight (increased risk) Adult screening measure, not a diagnosis; unsuitable for children or pregnancy. About 24.9: inside the WHO healthy range, but above the Asian cut-off of 23.
Results are estimates for general information, not financial, medical, legal, tax, or property advice. Confirm important figures with the relevant institution or a qualified professional.
BMI Calculator: frequently asked questions
Does the calculator tell me if I am overweight?
Yes, as a screening category. It shows two labels: one from the WHO international table (underweight below 18.5, healthy 18.5–24.9, overweight 25–29.9, obese 30 and above) and one from the WHO cut-offs for Asian populations (healthy 18.5–22.9, overweight 23–27.4, obese 27.5 and above). A BMI of 24.9 is therefore healthy by WHO but overweight by the Asian cut-offs. Share the number with a doctor or dietitian, who can interpret it for your age, build and health history.
Can I enter my height in feet and inches or weight in pounds?
The calculator accepts only kilograms and centimetres: weight from 2 to 500 kg and height from 50 to 272 cm. To convert, multiply feet by 30.48 and inches by 2.54 and add them, so 5 ft 7 in is about 170.2 cm. For pounds, use our Weight Converter or divide by about 2.2046. Enter plain numbers without units in the fields.
Is BMI accurate for athletes or muscular people?
Not always. BMI uses only weight and height, so it cannot tell muscle from fat. A muscular person may score high while being healthy, and an older adult with low muscle may score normal while carrying excess fat. Waist measurement and other checks give extra context that BMI alone misses.
Can I use this for a child or during pregnancy?
No. Children and teenagers need age- and sex-specific BMI percentile charts, which this tool does not provide. During pregnancy, weight changes for reasons BMI cannot reflect. In both cases, rely on a paediatrician, obstetrician or other qualified clinician rather than this adult number.
Is this medical advice?
No. The result is a general screening figure for adults and is not a diagnosis, treatment plan or personal recommendation. Health depends on many factors this tool does not measure. If you are concerned about your weight or health, speak with a doctor or registered dietitian before making major changes.
Is my data saved or shared?
No. The calculation runs locally in your browser, and the weight and height you enter are not sent to a server. Pressing Reset clears the form, and closing the page discards everything. You can copy the result yourself if you want to keep a record.