What Is BMI by Age?
BMI is calculated the same way regardless of age for adults, but age can influence how health professionals interpret weight-related risk.
By Age
BMI Calculator by Age
This BMI calculator by age helps you estimate body mass index and explore how age can affect the way BMI results are interpreted.
Your BMI Result
Fill in your height and weight, then click calculate to view your BMI result and healthy weight range.
BMI Formula by Age
Metric: BMI = weight (kg) ÷ height² (m²)
Imperial: BMI = (weight (lbs) ÷ height² (in²)) × 703
BMI Categories by Age
| Category | BMI Range | Health Risk |
|---|---|---|
| Underweight | < 18.5 | Possible nutritional deficiency |
| Normal Weight | 18.5 – 24.9 | Low risk |
| Overweight | 25 – 29.9 | Moderate risk |
| Obese | ≥ 30 | High risk |
Frequently Asked Questions
The Body Mass Index (BMI) is a screening tool used to identify whether an adult is underweight, at a healthy weight, overweight, or obese. It is calculated by dividing a person’s weight in kilograms by the square of their height in meters.
The formula does not change, but BMI may be interpreted differently depending on age and overall health context.
BMI can still be useful, though it may not fully reflect body composition changes that occur with age.
Yes. Adult BMI uses the same formula across age groups.
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