Adult BMI calculator
Calculate body mass index from weight and height, with unit conversions shown explicitly.
Formula & units
BMI (kg/m²) = weight (kg) ÷ [height (m)]²
Pounds are converted to kilograms with 0.45359237; inches are converted to centimeters with 2.54. Height in centimeters is divided by 100 before it is squared.
Worked example
Weight 70 kg and height 175 cm give BMI 22.86 kg/m².
What the result can tell you
This adult tool is for ages 20 and older. BMI is a screening measure, not a direct measure of body fat or insulin resistance. Pregnancy, muscle mass and individual clinical context affect interpretation. No weight target is generated.
Read the interpretation guide →
Sources for this method
Questions about Adult BMI
How do I calculate adult BMI?
Divide weight in kilograms by height in meters squared. For example, 70 kg and 1.75 m give BMI 22.86 kg/m².
Source: CDC · Adult BMI calculator (opens in a new tab) · Related calculator → · Link to answer
Does BMI measure body fat or insulin resistance?
BMI relates weight to height. It does not directly measure body fat or insulin sensitivity and should be considered alongside other health information.
Source: CDC · Adult BMI calculator (opens in a new tab) · Related calculator → · Link to answer
Can children use this BMI calculator?
This tool is for adults age 20 and older. Children and teens need an age- and sex-specific BMI assessment rather than adult interpretation.
Source: CDC · Adult BMI calculator (opens in a new tab) · Related calculator → · Link to answer
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