How to Use the BMI Calculator
Enter your height and weight to estimate body mass index and compare the result with standard adult BMI categories.
Practical Example
A person weighing 70 kg at 1.75 m has a BMI of about 22.9.
Factors That Affect the Result
BMI does not directly measure body fat and can be less representative for athletes, older adults, children or people with unusually high muscle mass.
Frequently Asked Questions
What BMI is considered normal?
For many adults, 18.5 to 24.9 is commonly classified as the normal range.
Does BMI diagnose health?
No. It is a screening metric, not a diagnosis.
Can muscular people have a high BMI?
Yes. Muscle mass can increase BMI without indicating excess body fat.
Related Tools
How to Interpret BMI
Body mass index relates weight to height using the formula weight in kilograms divided by height in meters squared. It is widely used as a screening measure because it is simple, but it does not directly measure body fat or distinguish muscle from fat mass. Two people with the same BMI can therefore have different body compositions. BMI categories are population-level reference ranges and may require different interpretation for children, pregnancy, older adults, highly muscular individuals and some clinical situations. A single BMI value should not be treated as a diagnosis. If you are tracking changes, use consistent height and weight measurements and consider other information such as waist measurement, fitness, medical history and professional assessment when relevant. Health decisions should not be based solely on an online BMI result.
How BMI Is Calculated
BMI is weight in kilograms divided by height in meters squared. It is a screening measure that relates body weight to height; it does not directly measure body-fat percentage, muscle mass or fat distribution.
Limits of BMI
BMI can classify people with very different body compositions similarly. Muscular individuals, older adults, pregnant people and some population groups may require additional context. Clinical assessment can include waist measures, medical history and other health indicators.
Interpreting a BMI Result
Adult BMI categories are screening ranges, not diagnoses. Appropriate interpretation can differ for children and adolescents because age- and sex-specific growth references are used. Health decisions should not rely on BMI alone.