BMI Calculator
Calculate your Body Mass Index and find out your weight category.
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24.2
Normal weight
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Frequently Asked Questions
What is BMI and what is it used for?
Body Mass Index (BMI) is a value calculated from weight and height: weight (kg) ÷ height (m)². The WHO uses it as a screening tool to classify weight status in adults. It is not a diagnosis, but a starting point for assessing metabolic and cardiovascular risk.
How is BMI calculated?
The formula is BMI = weight (kg) ÷ height (m)². For example, a 70 kg person who is 1.75 m tall has a BMI of 70 ÷ 3.0625 ≈ 22.9. In imperial units: BMI = (weight in lb ÷ height in in²) × 703. This calculator handles the conversion automatically.
What are the WHO BMI categories?
The WHO defines four categories for adults: below 18.5 = underweight, 18.5–24.9 = normal weight, 25.0–29.9 = overweight, 30.0 or above = obese. Obesity is further divided into Class I (30–34.9), Class II (35–39.9), and Class III (40+).
What is a normal BMI for adults?
The normal range is 18.5 to 24.9 for both men and women. A BMI in this range is associated with the lowest risk of weight-related metabolic and cardiovascular complications in the general adult population.
Does high BMI always mean obesity?
Not necessarily. Athletes with significant muscle mass may have a high BMI without excess fat. BMI does not distinguish between fat and lean mass, nor does it account for fat distribution. It is a population-level screening tool, not an individual diagnosis.
Is BMI accurate for all populations?
No. Health organizations in Asian countries use lower cutoff thresholds because metabolic risk appears at lower BMI values. BMI is also less accurate for children, pregnant women, older adults with muscle loss, and individuals with atypical body composition.
What measures complement BMI?
Waist circumference, waist-to-hip ratio, and body fat percentage (via DEXA or bioelectrical impedance) are more informative at the individual level. BMI does not account for bone density, fat distribution, or body composition.
Does this calculator replace medical advice?
No. BMI is a population-level screening metric for educational purposes only. It does not constitute a clinical diagnosis or medical evaluation. Consult a healthcare professional to interpret your result and make decisions about diet, exercise, or treatment.
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