Check your BMI band and read supportive information about underweight and eating disorders.
BMI is weight ÷ height². A BMI below 18.5 is underweight, but BMI alone cannot diagnose or rule out anorexia nervosa — diagnosis depends on behaviours, thoughts and health, not a single number.
This page gives your BMI and WHO category and explains what BMI can and cannot say about eating disorders. It deliberately gives no target weights, calorie advice or comparisons: those can be harmful for someone who is struggling with food or weight. If your BMI is low it shows a supportive message with places to get help.
Anorexia nervosa is a serious but treatable mental-health condition. Many people with eating disorders have a BMI in the normal range or above. If you or someone you know is restricting food, afraid of gaining weight or exercising compulsively, please reach out to a doctor or counsellor. For general BMI information see the BMI Calculator.
The calculator applies the standard published formulas step by step.
| Item | Value |
|---|---|
| BMI | 19.1 kg/m² |
| WHO category | Normal weight |
| What this means | Not underweight by BMI |
| BMI can show | BMI cannot show |
|---|---|
| Whether weight is below the healthy range for height | Eating behaviours or thoughts about food |
| A rough screening category | Muscle versus fat, or where fat is stored |
| A reason to speak to a doctor | Whether someone has an eating disorder |
No. Anorexia nervosa is diagnosed by a clinician from eating behaviours, fear of weight gain, body-image disturbance and health findings — not by BMI alone.
Yes. Anorexia, bulimia, binge-eating disorder and other eating disorders occur at every weight.
Skipping meals, intense fear of gaining weight, rigid food rules, compulsive exercise, withdrawing from social eating, dizziness, feeling cold and missed periods.
Speak to your doctor or a mental-health professional, or call Tele-MANAS on 14416, the government mental-health helpline.
In the US, the Alliance for Eating Disorders helpline is 1-866-662-1235. In the UK, contact Beat. Check the current numbers on their websites.
Choose a private moment, speak kindly about what you have noticed rather than their weight, listen without judgement and encourage them to see a doctor.
It uses the published formula: BMI = weight (kg) ÷ height (m)² The full method and a worked example are shown on this page.
No. The calculator gives general estimates for information and education. It cannot diagnose or treat anything, so please speak to a doctor or qualified professional about your own health.
Yes. Choose centimetres or feet and inches for height, and kilograms, pounds or stone for weight; the results are converted for you.
No. Everything is calculated in your browser and nothing you enter is uploaded or saved.
