What Is BMI and What Does It Really Tell You?
BMI is a quick screening number. Here is what it measures, where it falls short and how to use it sensibly.
How BMI is calculated
Body mass index divides weight in kilograms by height in metres squared. Adults with a BMI from 18.5 to 24.9 are classed as a healthy weight, 25 to 29.9 as overweight and 30 or more as obese.
Where BMI falls short
BMI cannot tell muscle from fat, so athletes can score as overweight. It also ignores where fat is stored, and thresholds may under-estimate risk in some Asian populations.
Using it well
Treat BMI as a starting point and pair it with waist measurements, blood pressure and blood tests. If your BMI is outside the healthy range, small steady changes in food and activity usually help more than crash plans.
Try it: BMI Calculator
Example with sample values. Open the full calculator →
Your BMI is 24.2, which is in the healthy range for adults. BMI is a screening tool and does not measure body fat directly.
Educational content only. This article does not replace advice from a qualified health professional. Medical disclaimer.