What does BMI measure?
BMI compares weight with height. It is a screening measure, not a diagnosis.
BMI Calculator
Workspace
Height and weight
Adults only. Children and teenagers need age-specific assessment.
Standard thresholds
Underweight< 18.5
Healthy weight18.5–<25
Overweight25–<30
Obesity (class 1)30–<35
Obesity (class 2)35–<40
Obesity (class 3)≥ 40
About BMI
BMI is a screening measure and does not directly measure body fat. It does not distinguish fat, muscle, or bone.
References: CDC adult BMI categories and NICE adult assessment guidance.
HelpGuide
How to use
- Enter your height and weight.
- Review your BMI and reference range.
HelpFAQs
Can children use this calculator?
No. Children and teenagers need age- and sex-specific BMI assessment.
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