BMI Calculator
Check your body mass index in metric or imperial units with WHO category labels.
Select the unit system that matches your measurements. Metric mode uses kilograms for weight and centimeters for height. Imperial mode uses pounds for weight and feet plus inches for height.
Enter your values and the calculator will compute your Body Mass Index using the standard formula. The result is rounded to one decimal place and paired with the WHO category: underweight, normal weight, overweight, or obese.
BMI is a screening tool, not a diagnosis of body fatness or health. Athletes, older adults, and pregnant people may get different interpretations from a healthcare provider.
Frequently asked questions
What is the BMI formula?
For metric units, BMI equals weight in kilograms divided by height in meters squared. For imperial units, multiply weight in pounds by 703, then divide by height in inches squared.
What are the standard BMI categories?
The WHO categories used here are: under 18.5 is underweight, 18.5 to 24.9 is normal weight, 25 to 29.9 is overweight, and 30 or above is obese.
Is this calculator accurate for children?
This calculator uses adult BMI categories. For children and teens, age and sex specific percentile charts are needed, so consult a pediatric growth chart instead.