BMI Calculator – Calculate Body Mass Index Online
Check a BMI score against the eating-disorder risk threshold.
About the Anorexic BMI Calculator
What is the Anorexic BMI Calculator?
An anorexic BMI calculator reports your BMI and flags whether it falls below 17.5, the figure cited in some screening criteria for anorexia nervosa.
Why use this calculator?
Weight is only one dimension of an eating disorder. This tool exists to raise awareness that a very low BMI deserves professional attention — it is not a diagnosis.
How to use it
- Enter your weight and height.
- Read your BMI and how it compares with the 17.5 threshold.
- If you or someone you know is struggling, seek professional help.
Formula
BMI = weight (kg) ÷ height (m)\u00b2
A low BMI without other symptoms has many causes including illness and genetics. Screening always involves clinical assessment.
Frequently Asked Questions
Does a BMI below 17.5 mean anorexia?
No. Diagnosis requires a full clinical picture including psychological symptoms. Many people with a low BMI do not have an eating disorder.
Where can someone get help?
Start with your doctor, or contact an eating-disorder charity such as NEDA (US) or Beat (UK). Early help improves outcomes.
Is this a medical diagnosis?
No. This tool provides general wellness information only. It is not a substitute for evaluation by a qualified healthcare professional.
Why do results differ from my doctor's measurements?
Clinical measurements use calibrated equipment and professional technique. Home estimates rely on formulas and self-reported values, so small differences are normal.
How often should I recalculate?
Recheck after meaningful changes such as weight gain or loss, a new workout routine, or every few months to track trends over time.
Do these formulas apply to everyone?
Most population formulas are less accurate for athletes, pregnant people, very young children and the elderly. Use them as a general guide.
Is this calculator free to use?
Yes. Every calculator on this site is completely free, with no hidden fees, no subscriptions and no limits on how many times you can use it.
How accurate are the results?
We use standard, widely accepted formulas and calculate in your browser using double-precision arithmetic. Results are rounded for readability, so treat them as reliable estimates rather than a guarantee. Real-world factors can vary the true figure.
Can I add this calculator to my own website?
Yes. Open this calculator page and use the "Add to your website" box in the sidebar to copy a ready-made iframe snippet, then paste it into any HTML page.
Does it work on a phone or tablet?
Yes. The layout is fully responsive, so it works on desktops, laptops, tablets and mobile phones, and every input adapts to touch screens.