BMI (Body Mass Index)
Weight-to-height ratio used to screen for underweight, healthy weight, overweight and obesity.
What is BMI (Body Mass Index)?
Weight-to-height ratio used to screen for underweight, healthy weight, overweight and obesity. BMI is intended for use in: Adults.
How to Use the BMI Calculator
- Enter Weight in kg.
- Enter Height in cm.
- Click Calculate to see your result and interpretation.
Formula & Version
This calculator uses formula version 1.0, last reviewed September 2026.
Clinical Considerations & Limitations
- Does not distinguish fat mass from lean mass — can misclassify athletes or very muscular individuals.
- Population thresholds differ by ethnicity (e.g. lower cut-offs are used for some Asian populations).
References
- Quetelet LAJ, 1832; WHO Expert Consultation, Lancet 2004 (BMI classification)
Frequently Asked Questions
What is BMI (Body Mass Index)?
Weight-to-height ratio used to screen for underweight, healthy weight, overweight and obesity.
Who is BMI intended for?
Adults. Always confirm applicability to your specific patient before use.
What are the limitations of BMI?
Does not distinguish fat mass from lean mass — can misclassify athletes or very muscular individuals. Population thresholds differ by ethnicity (e.g. lower cut-offs are used for some Asian populations).
What formula or reference does BMI use?
Quetelet LAJ, 1832; WHO Expert Consultation, Lancet 2004 (BMI classification)
Is BMI a diagnosis?
No. BMI produces a score or estimate to support clinical decision-making — it is not a diagnosis and should be interpreted alongside full clinical judgement.
