BMI calculator
Enter your height and weight in metric or imperial units to calculate your adult BMI. The result is a screening measure; it cannot decide whether a medicine is suitable for you.
What the BMI bands mean #
Common adult BMI categories are: below 18.5, underweight; 18.5 to below 25, healthy weight range; 25 to below 30, overweight; and 30 or above, obesity. These are screening categories, not a diagnosis or a judgement about you.
Health risks can occur at a lower BMI in some ethnic groups. The NHS adult BMI calculator includes ethnic background in its interpretation. Treatment criteria depend on the medicine, health conditions and care pathway.
Where BMI falls short #
BMI does not distinguish muscle from fat or show where body fat is carried. This calculator is for adults, and is not suitable for pregnancy or assessing children. A clinician may consider waist measurements, ethnicity, age, health conditions and medicines alongside BMI.
What to do with your result #
Discuss your result with a healthcare professional if you are concerned about your weight or health. Unintentional weight loss also warrants advice. Use the discussion checklist to prepare questions, or read how treatment suitability is assessed.
Understand your treatment options
Aero’s treatment prices and service inclusions will be confirmed before booking opens. Ask which prescribing, dispensing, delivery and follow-up costs are included in your quote.
Page information
- Summary
- Calculate adult BMI using metric or imperial units. Understand screening categories and limitations; a BMI result cannot decide treatment suitability.
- Publisher
- Aero Clinic, operated by AERO HEALTHCARE LTD.
- Editorial update
- Clinical review
- Pending. An editorial update is not a clinical sign-off.
Cite as: BMI calculator, Aero Clinic (https://www.cagri.co.uk), AERO HEALTHCARE LTD. https://www.cagri.co.uk/bmi-calculator. Editorial update: 4 November 2026. Clinical review pending.