BMI Calculator
Body Mass Index calculator for adults and children
Result
- Healthy BMI range: 18.5 kg/m2 – 25 kg/m2
- Healthy weight for the height: 59.9 kg – 81 kg
- BMI Prime: 0.8
- Ponderal Index: 11.1 kg/m3
Understanding Body Mass Index (BMI)
The Body Mass Index (BMI) Calculator can be used to calculate BMI value and corresponding weight status while taking age into consideration. BMI is a measurement of a person’s leanness or corpulence based on their height and weight, and is intended to quantify tissue mass. It is widely used as a general indicator of whether a person has a healthy body weight for their height.
BMI Categories for Adults
This is the World Health Organization’s (WHO) recommended body weight based on BMI values for adults. It is used for both men and women, age 20 or older.
| Classification | BMI Range (kg/m2) |
|---|---|
| Severe Thinness | < 16 |
| Moderate Thinness | 16 – 17 |
| Mild Thinness | 17 – 18.5 |
| Normal | 18.5 – 25 |
| Overweight | 25 – 30 |
| Obese Class I | 30 – 35 |
| Obese Class II | 35 – 40 |
| Obese Class III | > 40 |
How BMI is Calculated
BMI is calculated by dividing a person’s weight in kilograms by the square of their height in meters:
Metric Formula: BMI = weight (kg) / (height (m))2
US Formula: BMI = 703 × weight (lb) / (height (in))2
Limitations of BMI
While BMI is a useful screening tool, it has limitations:
- Doesn’t directly measure body fat
- May overestimate body fat in athletes with high muscle mass
- May underestimate body fat in older adults who have lost muscle
- Doesn’t account for differences in body composition between ethnic groups
Health Risks Associated with BMI
High BMI Risks: High blood pressure, type 2 diabetes, heart disease, stroke, certain cancers
Low BMI Risks: Malnutrition, osteoporosis, decreased immune function, fertility issues
BMI for Children and Teens
For children and teens (ages 2-20), BMI is interpreted differently than for adults. The CDC uses percentile ranges:
- Underweight: <5th percentile
- Healthy weight: 5th to 85th percentile
- Overweight: 85th to 95th percentile
- Obese: ≥95th percentile