Calculate your Body Mass Index instantly and understand what it means for your health — including the key limitations every dietitian knows.
Enter your height and weight to get your BMI and weight category.
Body Mass Index (BMI) is a numerical value calculated from a person's height and weight. It is one of the most widely used screening tools in healthcare and public health, providing a quick, cost-free estimate of whether someone falls within an underweight, healthy, overweight, or obese weight range.
| BMI Range | Category | Health Risk |
|---|---|---|
| < 18.5 | Underweight | Malnutrition, bone loss, immune dysfunction |
| 18.5 – 24.9 | Healthy Weight | Lowest risk for most chronic diseases |
| 25.0 – 29.9 | Overweight | Moderate risk for metabolic conditions |
| 30.0 – 34.9 | Obese (Class I) | High risk for T2D, CVD, hypertension |
| 35.0 – 39.9 | Obese (Class II) | Very high risk |
| ≥ 40.0 | Obese (Class III) | Extremely high risk |
While BMI is a convenient screening tool, dietitians know it has significant limitations that can lead to misclassification:
Use BMI as a starting point, not a definitive measure. Pairing BMI with waist circumference, body fat percentage, and clinical labs gives a much more complete picture of health.
BMI is a useful, accessible screening tool — but it is just one piece of the puzzle. Work with a Registered Dietitian to interpret your results in the context of your full health picture, lifestyle, and goals.
This tool is for informational purposes only and does not constitute medical or dietary advice.