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BMI Formula:
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Body Mass Index (BMI) is a simple index of weight-for-height that is commonly used to classify underweight, overweight and obesity in adults. It is defined as the weight in kilograms divided by the square of the height in meters (kg/m²).
The calculator uses the standard BMI formula:
Where:
Note: BMI cutoffs are lower for Asian populations as they have higher health risks at lower BMI levels compared to Caucasians.
| BMI (kg/m²) | Category |
|---|---|
| < 18.5 | Underweight |
| 18.5 - 22.9 | Normal weight |
| 23 - 24.9 | Overweight (At risk) |
| 25 - 29.9 | Overweight (Moderately obese) |
| ≥ 30 | Obese (Severely obese) |
Tips: Enter weight in kilograms and height in meters. For height in centimeters, divide by 100 (e.g., 175 cm = 1.75 m).
Q1: Why different BMI categories for Asia Pacific?
A: Asian populations have higher body fat percentage at lower BMI levels and higher risk of type 2 diabetes and cardiovascular disease at lower BMI compared to Caucasians.
Q2: Is BMI accurate for everyone?
A: BMI may overestimate body fat in athletes and underestimate it in older people who have lost muscle mass. Waist circumference should also be considered.
Q3: What are the health risks of high BMI?
A: Increased risk of type 2 diabetes, hypertension, cardiovascular disease, stroke, and certain cancers.
Q4: How often should I check my BMI?
A: For most adults, checking every 6-12 months is sufficient unless you're actively trying to lose or gain weight.
Q5: Should children use this calculator?
A: No, children and teens need age- and sex-specific BMI percentiles as their body composition changes with growth.