BMI Calculator
What is BMI?
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.
The value obtained from the calculation of BMI is used to categorize whether a person is underweight, normal weight, overweight, or obese depending on what range the value falls between.
BMI Calculator
Calculate your Body Mass Index (BMI)
ages: 2 - 120
cm
kg
Adult BMI Categories
WHO recommendations for ages 20+
| Classification | BMI (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 |
Children & Teens BMI Categories
CDC recommendations for ages 2-20
| Category | Percentile Range |
|---|---|
| Underweight | <5% |
| Healthy weight | 5% - 85% |
| At risk of overweight | 85% - 95% |
| Overweight | >95% |
BMI Formula
US Customary System (USC)
BMI = 703 × weight(lb) / height²(in)
Example (5'10", 160 lbs):
BMI = 703 × 160 / 70² = 23.0
Metric System (SI)
BMI = weight(kg) / height²(m)
Example (1.778m, 72.57kg):
BMI = 72.57 / 1.778² = 23.0
Note: While BMI is a useful screening tool, it is not diagnostic of body fatness or overall health. Additional factors such as muscle mass, bone density, age, sex, ethnicity, and other factors influence healthy weight ranges. Consult with healthcare providers for proper evaluation.