How to use this calculator
Enter height and weight in the selected units to calculate body mass index. Read the number as a screening measure alongside the calculator’s stated limitations.
How the estimate is calculated
BMI is weight in kilograms divided by height in metres squared. Imperial inputs are converted before calculation. The value describes weight relative to height; it does not directly measure body fat.
What the estimate cannot tell you
BMI cannot distinguish muscle from fat or describe fat distribution. The CDC adult category system applies to adults aged 20 and older; younger people need age-appropriate interpretation. Pregnancy and individual medical circumstances also require context. A category label is not a diagnosis or a target weight prescription.
Worked example
At 70 kg and 1.75 m, BMI is 70 ÷ 1.75² = 22.86, approximately 22.9.