BMI Calculator
Calculate your Body Mass Index (BMI) using your height and weight.
Enter Your Information
Your BMI Result
BMI
Enter your height and weight to calculate your BMI.
BMI calculated. Standard adult BMI categories are not intended for people under 18. Children and teenagers are evaluated using BMI-for-age percentiles based on age and sex. Consult a qualified healthcare professional or use appropriate pediatric growth charts for interpretation.
BMI Range
< 18.5 Healthy
18.5–24.9 Overweight
25–29.9 Obesity
30+
Enter your height and weight to calculate your BMI.
How to Use the BMI Calculator
- Select Metric or Imperial units.
- Enter your age if you want to provide age context.
- Optionally select Male or Female.
- Enter your height and weight.
- Click Calculate BMI, or change an input to update the result automatically.
- Review your BMI and the applicable interpretation.
- Review the standard BMI range and estimated BMI-based weight range when applicable.
- Use Copy Results if you want to save or share the calculation.
What Is BMI?
BMI, or Body Mass Index, is a screening measurement calculated from a person's weight and height. It is commonly used to place adults into broad weight categories.
BMI does not directly measure body fat and should not be treated as a complete measure of health. Factors such as muscle mass, body composition, age, pregnancy and individual health conditions can affect how BMI should be interpreted.
BMI Formula
BMI is calculated using weight and height.
For metric measurements, BMI equals weight in kilograms divided by height in meters squared.
For imperial measurements, BMI can be calculated as pounds multiplied by 703, divided by height in inches squared.
Adult BMI Categories
| BMI Range | Category |
|---|---|
| Below 18.5 | Underweight |
| 18.5 – 24.9 | Healthy Weight |
| 25.0 – 29.9 | Overweight |
| 30.0 and above | Obesity |
These are standard adult BMI categories. They are not intended for interpreting BMI in children and teenagers.
BMI Calculation Examples
Example 1
Height: 170 cm
Weight: 70 kg
BMI: 24.2
Category: Healthy Weight
Example 2
Height: 170 cm
Weight: 80 kg
BMI: 27.7
Category: Overweight
Example 3
Height: 170 cm
Weight: 60 kg
BMI: 20.8
Category: Healthy Weight
BMI Limitations
BMI is a screening measure rather than a complete assessment of health. It does not directly account for:
- Muscle mass
- Body fat distribution
- Bone density
- Individual health conditions
- Pregnancy
- Age-related changes in body composition
Athletes and people with high muscle mass may have a higher BMI without having excess body fat.
When Can You Use a BMI Calculator?
A BMI calculator can be useful for general health screening, understanding standard adult BMI categories, tracking changes in weight and height, educational purposes and fitness planning.
BMI is best considered alongside other health information rather than used as a standalone medical conclusion.
Age, Gender and BMI
This calculator allows you to enter age and select Male or Female as additional context. Gender does not change the adult BMI formula or the numerical BMI result.
For adults, BMI is calculated from height and weight. For children and teenagers, BMI interpretation requires age- and sex-specific BMI-for-age growth charts rather than adult BMI thresholds.