Definition
BMI = weight in kilograms divided by height in metres squared. Adult BMI categories are screening categories, not diagnoses.
How it affects calculator results
The same BMI formula is used across metric and imperial inputs, but the interpretation depends on whether the person is an adult and whether BMI is appropriate for the situation.
What to check
- Use adult BMI categories only for adults.
- Convert height correctly before using the formula.
- Do not use BMI alone for children, pregnancy, athletes or medical decisions.
Limitations
BMI does not directly measure body fat, muscle, fat distribution or individual health.
FAQ
Is BMI a diagnosis?
No. BMI is a screening index that can point to follow-up questions, not a complete health assessment.
Why can BMI mislead?
It uses only height and weight, so it cannot tell whether weight comes from fat, muscle, fluid or other body composition differences.