BMI Calculator
Calculate your Body Mass Index instantly. Enter your height and weight to find out your BMI category and what it means for your health.
How BMI Is Calculated
BMI = weight (kg) ÷ height² (m²). It was developed by Belgian mathematician Adolphe Quetelet in the 1830s as a quick population-level screening tool — not as an individual health diagnostic. That distinction matters.
The WHO uses BMI categories to identify weight-related health risks across populations. For individuals, it's less precise. A 2016 study in the International Journal of Obesity found that roughly 54 million Americans classified as "overweight" or "obese" by BMI were actually metabolically healthy.
BMI Limitations Worth Knowing
BMI doesn't differentiate between muscle and fat. It doesn't account for age, gender, ethnicity, or body composition. Athletes routinely have "overweight" BMIs. Older adults may have "normal" BMIs but high body fat. If you want a fuller picture, pair BMI with our Body Fat Calculator and Ideal Weight Calculator.
⚠️ Medical Disclaimer
This tool provides estimates for informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making health decisions. Results may vary based on individual factors not captured by this calculator.