BMI Calculator
Calculate adult BMI with metric or US measurements.
Calculate adult BMI
Your result
Body mass index
- Adult screening category
- Healthy weight
- Screening weight range
- 56.7–76.3 kg
BMI is a screening measure, not a diagnosis or direct measure of body fat.
Your entries and results stay in this browser. This tool does not send, save, or add them to the page address.
How to use the BMI calculator
Choose metric or US units, then enter your current height and weight. The calculator reports BMI to one decimal place, the corresponding standard adult screening category, and the weight range associated with BMI values from 18.5 through 24.9 at the entered height.
Use measurements taken without heavy clothing or shoes when practical. Small measurement differences can change a result near a category boundary.
Understanding a BMI result
Body mass index is a ratio of weight to height. Health professionals and public-health organizations use it as a quick screening measure because it is simple and consistent, not because it directly measures body composition.
The categories shown here are adult screening ranges. A category does not diagnose a condition or determine an individual’s health. BMI can classify muscular people at a higher level and may miss health risks in people with less muscle mass.
Important limitations
This calculator is not intended for children or teenagers, whose BMI is assessed using age- and sex-specific growth charts. Pregnancy, swelling, amputation, athletic training, age-related muscle loss, and other factors can also make standard adult BMI categories less informative.
Consider BMI alongside other information such as medical history, waist measurement, blood pressure, laboratory results, activity, nutrition, and guidance from a qualified healthcare professional. Do not use this estimate to start or stop medical treatment.
Frequently asked questions
What formula does this BMI calculator use?
Metric BMI is weight in kilograms divided by height in meters squared. The US-unit calculation multiplies weight in pounds by 703 and divides by height in inches squared.
What do the adult BMI categories mean?
Standard screening categories are below 18.5 for underweight, 18.5 through 24.9 for healthy weight, 25 through 29.9 for overweight, and 30 or higher for obesity. They are screening ranges, not diagnoses.
Is BMI accurate for every person?
No. BMI does not directly measure body fat or distinguish fat from muscle, bone, or fluid. Its interpretation can be limited for athletes, older adults, pregnant people, and some populations.
Should children use this BMI calculator?
No. BMI for children and teenagers is interpreted using age- and sex-specific percentiles. This calculator only applies the standard categories used to screen adults.