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BMI Calculator
Calculate your Body Mass Index, see your WHO category, and find your healthy weight range — all computed locally in your browser.
Imperial: BMI = (weight_lbs × 703) / height_in² |
Metric: BMI = weight_kg / height_m²
| Category |
BMI Range |
|
Underweight
|
< 18.5 |
|
Normal weight
|
18.5 – 24.9 |
|
Overweight
|
25.0 – 29.9 |
|
Obese Class I
|
30.0 – 34.9 |
|
Obese Class II
|
35.0 – 39.9 |
|
Obese Class III
|
≥ 40.0 |
Healthy Weight Range
—
BMI 18.5 – 24.9 for your height
Weight to Lose / Gain
—
to reach the normal range
BMI Prime
—
Ratio to upper normal limit (24.9). <1 = below normal range.
ℹ️
BMI has limitations. It does not account for muscle mass, bone density, age, sex, or ethnicity. Athletes may have a high BMI without excess body fat. Use this as a general guideline and consult a healthcare professional for a complete assessment.
Understanding Your BMI Results
Body Mass Index (BMI) is a screening measure calculated from your height and weight. It provides a quick way to categorize whether you're in a healthy weight range, but it's a population-level screening tool, not a diagnostic measure of individual health.
BMI Categories (WHO Standard)
- Underweight: Below 18.5 — may indicate nutritional deficiency or other health issues
- Normal weight: 18.5–24.9 — associated with lowest risk of weight-related disease
- Overweight: 25.0–29.9 — increased risk of metabolic conditions
- Obese Class I: 30.0–34.9 | Class II: 35.0–39.9 | Class III: 40+
Limitations of BMI
BMI doesn't distinguish between muscle and fat. A muscular athlete may be classified "overweight" while actually having low body fat. BMI is also less accurate for elderly individuals (who may have lost muscle mass) and for certain ethnic groups where the same BMI corresponds to different metabolic risk. For a fuller picture, combine BMI with waist circumference and body fat percentage.
Healthy BMI for Adults
For most adults, a BMI of 18.5–24.9 is considered healthy. Some research suggests 22–23 is associated with the lowest mortality risk. Asian populations may have higher metabolic risk at lower BMI values — some guidelines use 23 as the overweight threshold for Asian adults.
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