About this bmi calculator
Calculate body mass index using height and weight, then see the corresponding adult screening category. Metric and imperial inputs are supported and converted before calculation. This tool uses CDC adult categories for people aged 20 and over. BMI is a broad screening measure and does not directly measure body fat or individual health. Consider the result alongside other information and professional advice when making decisions about your health.
How it works
BMI = weight in kilograms / (height in meters)². Categories use the unrounded result: below 18.5, underweight; 18.5 to below 25, healthy weight; 25 to below 30, overweight; 30 and above, obesity.
Try these examples
70 kg, 175 cm
BMI 22.86 · Healthy weight
90 kg, 180 cm
BMI 27.78 · Overweight
Limitations & privacy
Only for adults aged 20 or older. Not a diagnostic test, body-fat measurement, or pregnancy assessment. Muscularity and other individual factors can affect interpretation. Consult a qualified healthcare professional. Content awaits human review before indexing.
Inputs and results stay in this browser. Only tool identifiers are stored for your recently used tools. You can clear that history from the directory.
Category reference: CDC adult BMI categories. Source checked September 12, 2026.
A few good questions
Why is the minimum age 20?
CDC adult categories apply to ages 20 and over. Children and teens use age- and sex-specific percentiles.
Does BMI measure body fat?
No. It is a ratio of weight to squared height.
Can I use pounds and inches?
Yes. Choose Imperial and the inputs are converted to kilograms and centimeters.
Updated September 12, 2026