Free Tool
BMI Calculator.
Calculate your Body Mass Index using metric or imperial units. Get your score, WHO category, healthy weight range, BMI Prime, and Ponderal Index instantly.
Your BMI
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Category
— 1518.525303540+
Healthy Range
— kg
BMI Prime
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BMI is a screening tool, not a diagnostic measure. Consult a healthcare professional for medical advice.
How to interpret your BMI.
| BMI Range | Category | Health Risk |
|---|---|---|
| < 18.5 | Underweight | Malnutrition, osteoporosis, anemia |
| 18.5 – 24.9 | Normal weight | Lowest risk |
| 25.0 – 29.9 | Overweight | Moderate increased risk |
| 30.0 – 34.9 | Obese Class I | High risk |
| 35.0 – 39.9 | Obese Class II | Very high risk |
| ≥ 40.0 | Obese Class III | Extremely high risk |
Frequently asked questions.
What BMI range is considered healthy?
For adults, a BMI of 18.5–24.9 is healthy. This range is associated with the lowest all-cause mortality risk in most population studies.
What does BMI Prime mean?
BMI Prime is your BMI divided by 25 (the upper limit of normal). A value of 1.0 means you are at the boundary of healthy/overweight. Below 1.0 is healthy; above 1.0 is overweight.
Is a BMI calculator accurate for athletes?
Athletes may register an elevated BMI due to higher muscle mass. BMI does not distinguish fat mass from muscle mass, so body fat percentage is a better metric for athletes.
What is the Ponderal Index?
The Ponderal Index (PI) is a refinement of BMI: weight (kg) divided by height (m) cubed. It scales more accurately with height than BMI, especially for very tall or very short individuals.