BMI Calculator
The same number is classified differently depending on the standard. Here are both.
Reading your result
Fill in every field and the steps will be spelled out here.
How it is calculated
Thresholds are not universal. The WHO puts overweight at 25 and obesity at 30. Korean guidelines put pre-obesity at 23 and obesity at 25, on the evidence that people of Asian descent face metabolic risk at a lower BMI. A BMI of 24 is therefore classified two different ways depending on which table you read.
BMI cannot tell muscle from fat. It uses only height and weight, so a heavily trained person can register as overweight with very little body fat, while someone with low muscle and high visceral fat can sit comfortably in the normal range. Treating the label as a health verdict is where it misleads.
Waist circumference adds what BMI misses. Fat carried around the abdomen carries markedly higher metabolic risk than the same weight distributed elsewhere. A normal BMI with a large waist measurement is still worth acting on.
It does not apply to children, adolescents or pregnancy. Growth-stage assessment uses age- and sex-specific percentiles, and pregnancy uses separate weight-gain guidance based on pre-pregnancy BMI.
Frequently asked questions
Why are the Korean thresholds lower?
Studies show that at the same BMI, people of Asian descent tend to carry more body fat and face higher rates of diabetes and hypertension. Korean guidelines therefore introduce a pre-obesity band starting at 23.
I train regularly and my BMI says overweight.
BMI cannot distinguish muscle from fat, and muscle is denser. A body composition measurement will give a far more useful picture than BMI alone.
Is a normal BMI enough on its own?
Not necessarily. Low muscle mass with high visceral fat produces a normal BMI while carrying real risk. Waist circumference is worth measuring alongside it.
BMI uses only height and weight, so it cannot account for muscle mass, fat distribution, age or sex. It is not a diagnosis, and it does not apply to children, adolescents or pregnancy. Speak to a clinician about any health concern.