Anorexic BMI Calculator
Calculate BMI and see how it relates to clinical thresholds used in the diagnosis of anorexia nervosa. This is a screening tool, not a diagnosis.
How to use the Anorexic BMI Calculator
- Enter your inputs into the Anorexic BMI Calculator above.
- Results update instantly as you type — no submit button needed.
- Adjust any value to see how the result changes in real time.
The clinical BMI thresholds
BMI = Weight (kg) / Height (m)² · · · DSM-5 severity: Mild ≥17, Moderate 16–16.99, Severe 15–15.99, Extreme <15
BMI alone does not diagnose anorexia — DSM-5 requires restrictive food intake, intense fear of weight gain and body image disturbance. The BMI thresholds describe severity once a diagnosis is made.
Worked example
A 5'6" (1.68 m) adult weighing 95 lb (43 kg): BMI = 43 / 1.68² = 15.2 — within the "severe" range under DSM-5 anorexia severity criteria. Clinical evaluation is essential.
Frequently asked questions
Is low BMI sufficient for diagnosis?
No — DSM-5 requires three criteria: significantly low weight, intense fear of gaining weight, and disturbed self-perception. Some patients with anorexia have higher BMIs (atypical anorexia).
When should I get professional help?
Immediately if you or someone you know has BMI under 17.5, is intentionally restricting food, or experiences anxiety about eating. NEDA helpline (US): 1-800-931-2237.
What is the appropriate use of this calculator?
As an information tool for understanding clinical thresholds. It is not a substitute for evaluation by a qualified eating disorder clinician — call a professional for any concern.