BMI Calculator
Calculate adult body mass index from height and weight using metric or imperial units, with a BMI category and reference weight range.
BMI calculator
Calculate adult body mass index from height and weight using metric or imperial units.
BMI
BMI category
Reference weight range
Based on BMI 18.5–24.9 for the entered height.
How BMI is calculated
Body mass index compares weight with height. In metric units, BMI is calculated as weight in kilograms divided by height in meters squared.
Common adult BMI categories are underweight below 18.5, healthy weight from 18.5 to 24.9, overweight from 25 to 29.9, and obesity at 30 or above.
BMI is a screening measure and does not directly measure body fat, muscle mass, fitness or overall health.
Important
This calculator is intended for general informational use by adults. BMI may not be an appropriate measure for children, pregnancy, athletes with high muscle mass or some medical situations. It is not a diagnosis or individualized health recommendation.
How to use it
Choose metric or imperial units, enter your height and weight, then calculate BMI. The result includes the BMI value, standard adult category and a reference weight range for the entered height.
Privacy
Calculations are performed locally in your browser. The values you enter are not submitted to Muft.
Tool behavior last checked Aug 23, 2026.