Medically reviewed by Suzanne Fisher, RD Key Takeaways Body mass index (BMI) is a calculation used to estimate your body fat.

If your BMI reading has ever felt off — like it didn’t quite match how you look or feel — you’re not the only one questioning it. A string of studies published this year has doctors and researchers ...

Body mass index (BMI) is a measure of body fat based on your weight in relation to your height, and applies to most adult men and women aged 20 and over. For children aged 2 and over, BMI percentile ...