Anorexic BMI Calculator
This tool provides a reference table of BMI ranges used clinically to assess underweight severity. A BMI below 17.5 is o...
Medical Tool: BMI is a screening measure, not a diagnostic tool. Consult a healthcare provider for personalized assessment.
| BMI Range | Category |
|---|---|
| < 16 | Severe Thinness |
| 16 – 17 | Moderate Thinness |
| 17 – 18.5 | Mild Thinness |
| 18.5 – 25 | Normal Weight |
| 25 – 30 | Overweight |
| 30 – 35 | Obese Class I |
| 35 – 40 | Obese Class II |
| ≥ 40 | Obese Class III |
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How It Works
This tool provides a reference table of BMI ranges used clinically to assess underweight severity. A BMI below 17.5 is one of the diagnostic criteria for anorexia nervosa. Severe underweight (BMI <15) requires urgent medical attention.
Quick Reference
BMI < 17.5
Clinical threshold
Anorexic range
BMI 17.5-18.5
Below threshold
Underweight
BMI 18.5-24.9
Healthy range
Normal weight
Tips & Shortcuts
BMI is one component of eating disorder assessment — behavior, psychology, and medical history are equally important.
Recovery from anorexia is possible with proper treatment. Early intervention significantly improves outcomes.
If you are concerned about your weight or relationship with food, speak with a doctor or eating disorder specialist.
Common Mistakes
Diagnosing an eating disorder by BMI alone
Clinical diagnosis requires assessment by a qualified professional. People at normal BMI can have serious eating disorders.
Using BMI thresholds as weight goals
BMI ranges are clinical reference points, not targets. A healthcare provider should guide any weight-related goals.
Frequently Asked Questions
A BMI below 15 is classified as severely underweight and corresponds to clinical thresholds for anorexia nervosa. A BMI below 17.5 is one of the diagnostic criteria.
In the US, contact the National Alliance for Eating Disorders helpline at 1-866-662-1235 (Mon–Fri, 9am–7pm ET). Crisis Text Line: text HOME to 741741.
No. Clinical diagnosis requires assessment by a qualified professional. People with eating disorders can have a BMI in the normal or overweight range.
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