BMI Calculator
Metric & ImperialCalculate your Body Mass Index instantly. Get your BMI category, healthy weight range, and personalised health tips. Supports both metric and imperial units.
Unit System
Your Details
Gender
Height
170 cm
Weight
70.0 kg
Ideal Weight
53–72 kg
Normal weight · BMI 18.5 – 24.9
Great job! Maintain your weight through balanced diet and regular exercise.
BMI Scale
Healthy Weight Range for Your Height
Minimum
53 kg
BMI 18.5
Maximum
72 kg
BMI 24.9
Your weight is within the healthy range for your height. 🎉
How is BMI Calculated?
BMI uses a simple formula based on your height and weight:
Metric
BMI = kg ÷ m²
Weight (kg) ÷ Height² (metres)
Imperial
BMI = (lb ÷ in²) × 703
Weight (lb) ÷ Height² (inches) × 703
Measure Height
Stand straight against a wall and measure from floor to the top of your head.
Measure Weight
Use a calibrated scale in the morning, before eating, for the most accurate reading.
Calculate BMI
Enter your values above. Our calculator instantly gives you your BMI and category.
BMI Categories (WHO Standard)
The World Health Organisation defines the following BMI ranges for adults 20 years and older:
| BMI Range | Category |
|---|---|
| Below 18.5 | Underweight |
| 18.5 – 24.9 | Normal weight |
| 25.0 – 29.9 | Overweight |
| 30.0 – 34.9 | Obese (Class I) |
| 35.0 – 39.9 | Obese (Class II) |
| 40.0+ | Obese (Class III) |
Limitations of BMI
Doesn't Measure Fat
BMI can't distinguish between muscle and fat. Muscular athletes may have high BMI despite low body fat.
Age Not Considered
Older adults tend to have more body fat at the same BMI. A lower BMI may still carry risks for elderly individuals.
Ethnicity Differences
South Asians may face health risks at lower BMI thresholds (23+) compared to Western populations.
Not for Pregnant Women
BMI is not applicable during pregnancy. Consult your doctor for appropriate weight gain guidance during pregnancy.
Frequently Asked Questions
What is BMI and how is it calculated?
BMI (Body Mass Index) is a value derived from a person's weight and height. It is calculated by dividing weight in kilograms by the square of height in metres: BMI = kg/m². It is used as a screening tool for weight categories.
Is BMI an accurate measure of body fat?
BMI is a useful screening tool but not a diagnostic measure. It does not account for muscle mass, bone density, or fat distribution. Athletes may have a high BMI without excess body fat. Consult a doctor for a complete health assessment.
What is a healthy BMI for Indians?
The WHO standard uses 18.5–24.9 as normal. However, some studies suggest that for South Asians (including Indians), a BMI above 23 may indicate increased health risks. Consult a healthcare provider for personalised advice.
Does BMI differ for men and women?
Standard BMI ranges are the same for adult men and women. However, women naturally have more body fat than men at the same BMI. Body fat percentage measurements can give a more accurate picture for each gender.
What is the BMI for children?
BMI for children (2–19 years) is interpreted differently using age and gender-specific percentile charts. A standard adult BMI calculator is not appropriate for children. Consult a paediatrician for children's weight assessment.