Calculate your BMI and see how it relates to underweight thresholds. This tool provides educational information only.
This calculator estimates your Body Mass Index (BMI) and provides context for underweight categories. While a BMI below 18.5 is classified as underweight, anorexia nervosa typically involves a BMI of 17.5 or lower. This tool helps illustrate the weight thresholds used in clinical settings but should never replace professional medical evaluation.
In clinical settings, a BMI of 17.5 or below is commonly used as one of several indicators for anorexia nervosa assessment. However, diagnosis requires a comprehensive evaluation by a qualified mental health professional. BMI alone cannot determine whether someone has an eating disorder.
A BMI of 18.5 is considered the lower threshold of the normal weight range. The weight corresponding to this BMI varies by height. For a person 170 cm tall, the minimum healthy weight is about 53.5 kg (118 lbs). Falling below this threshold does not automatically indicate an eating disorder, but it may warrant a discussion with a healthcare provider.