BMI Calculator
BMI compares weight with height and provides a screening measure. It does not directly measure body fat or diagnose a disease.
BMI assessment tool
BMI compares weight with height and provides a screening measure. It does not directly measure body fat or diagnose a disease. A clinician interprets it alongside symptoms, examination, weight history, and other health measures.
Eligibility: BMI assessment tool
Adult BMI categories apply to adults 20 and older. Children and teens use BMI-for-age percentiles based on age and sex. Pregnancy, high muscle mass, edema, and other factors can limit interpretation. Health risk at the same BMI can vary across people.
What to expect: BMI assessment tool
Measure height and weight accurately and select the age-appropriate method. Review waist measures, blood pressure, glucose, lipids, activity, and nutrition when relevant. Use the result to start a health discussion rather than diagnose a condition or choose a drug automatically.
Preparing for your appointment
Bring accurate height and weight, recent changes, medicines, and relevant health tests. A calculator itself needs no medical procedure or fasting. Tell the clinician if weighing causes distress.
Risks and when to seek help
Unexplained weight loss, rapid gain with swelling, or a concerning child growth trend needs medical assessment. BMI alone should not drive a restrictive diet or medication decision.
Follow-up and treatment review
Repeat measurements when useful for growth, treatment, or health monitoring. Use consistent methods and assess trends. There is no universal need to calculate BMI every day.
Appointments, costs and coverage
Confirm the exact service, clinician, formulation, appointment, and refill route before booking. The evaluation, tests, medicine, administration, and follow-up may have separate costs and benefits. Ask for current estimates and required records. An FDA-approved drug or a clinic address does not establish pharmacy stock, onsite treatment, coverage, or a prescription. If access changes, contact the treating team before interrupting treatment.
Questions about your care
What is a BMI calculator?
A BMI calculator uses height and weight to calculate body mass index. It provides a screening number, not a direct body-fat measurement or a diagnosis. Adults use adult categories, while children need age- and sex-specific interpretation. Use accurate measurements and review the result with other health information.
Is BMI different for men and women?
Standard adult BMI cutoffs are the same for men and women, but body composition and health risk can differ. Pediatric BMI interpretation uses age and sex. The number should be considered alongside other health information.
Can BMI be used for children and teenagers?
Children and teenagers use BMI-for-age percentiles based on age and sex, not adult BMI cutoffs. Interpret the growth trend with the pediatric clinician. Adult weight-loss goals should not be applied to a child’s calculator result.
What are the limitations of using BMI?
BMI does not directly measure body fat or distinguish muscle from fat. Waist measurements, examination, and other assessments may add information. Pregnancy, high muscle mass, edema, and age can affect interpretation. No single measurement replaces a health assessment.
How often should BMI be calculated?
BMI can be recalculated when weight or height measurements change or during a clinician-planned health review. There is no universal requirement to check it every day. For children, growth trends and age- and sex-specific percentiles matter more than applying adult categories; the clinician chooses the useful follow-up interval.
Can BMI be influenced by ethnicity or race?
Health risk and body composition can differ between people at the same BMI, including across racial and ethnic groups. BMI is a screening tool. A clinician reviews other risk factors rather than treating the adult category as a complete risk assessment.