About the BMI Calculator
Body mass index (BMI) is a simple screening number that relates weight to height. It's a rough, general indicator — not a measure of health, fitness, or body composition. This tool estimates your BMI and shows the healthy-weight range for your height.
How it’s calculated
BMI = weight (kg) ÷ height (m)². Imperial inputs are converted to metric first. The healthy-weight range corresponds to BMI 18.5–24.9 for your height.
Example calculation
Someone 170 cm tall weighing 70 kg has a BMI of about 24.2, within the healthy-weight range (roughly 53–72 kg for that height).
Frequently asked questions
What is a healthy BMI?
For adults, a BMI between 18.5 and 24.9 is generally described as the healthy-weight range. BMI is a screening estimate only and doesn't account for muscle, age, sex, or body composition.
Is BMI accurate?
BMI is a general screening tool, not a diagnosis. Very muscular people may have a high BMI without excess fat, and it doesn't capture where weight is carried. For a fuller picture, talk to a healthcare professional.
Does BMI work for children or athletes?
Standard adult BMI categories don't apply well to children, teens, athletes, or during pregnancy. Speak with a doctor for interpretation in those cases.
This tool provides a general, informational estimate only. It is not medical advice and cannot diagnose, treat, or replace guidance from a qualified healthcare professional. Individual health depends on many factors this estimate does not capture. If you have questions about your health, talk to a doctor.