BMI Calculator
Check Your Body Mass Index
Enter your measurements for an adult BMI estimate, a clear category breakdown, and practical context.
BMI Calculator FAQs
1. What is BMI and how is it calculated?
BMI (Body Mass Index) is a screening measure that compares a person’s weight with their height. It helps identify weight categories but cannot determine overall health on its own.
BMI Formula:
BMI = Weight (kg) ÷ [Height (m) × Height (m)]
For example, a person weighing 70 kg with a height of 1.70 m has a BMI of approximately 24.2.
2. What is a healthy BMI range for adults?
For most adults, a BMI between 18.5 and below 25 falls within the standard healthy weight category. A BMI below 18.5 is classified as underweight. However, BMI is only a screening tool, and factors such as muscle mass, waist measurements and medical history also matter.
3. What BMI is considered overweight or obese?
Under standard adult classifications, a BMI of 25 to below 30 is considered overweight, while 30 or above falls within the obesity category. These ranges help assess weight status but do not diagnose an individual health condition.
4. Are BMI ranges different for Indian and South Asian adults?
Yes. Some health guidelines use lower BMI thresholds for South Asian populations because cardiometabolic risks can occur at lower BMI levels. NICE recommends 23 to below 27.5 for overweight and 27.5 or above for obesity in these populations. These thresholds should be interpreted alongside other health factors.
5. Is BMI accurate for athletes and people with high muscle mass?
Not always. BMI cannot distinguish muscle from fat, so athletes and people with greater muscle mass may have a higher BMI without having excessive body fat. Waist measurements, body composition and other health indicators can provide additional context.
6. Can BMI measure body fat directly, and is it suitable for children?
No. BMI does not directly measure body fat or show where fat is distributed. It is a useful screening measure rather than a diagnostic test. For children and teenagers aged 2–19, BMI must be interpreted using age- and sex-specific percentiles instead of standard adult categories. BMI also requires special interpretation during pregnancy.