Anorexic BMI Calculator · Practical guide
Is My Weight Too Low for My Height?
If your BMI falls below 18.5, your weight is under the healthy minimum for your height.
At a glance
The Rule of Thumb
Your weight is too low for your height when your BMI drops below 18.5. Equivalently, the minimum healthy weight for any height is 18.5 times your height in meters squared. For example, at 5 foot 7 the healthy range starts at about 118 lb — anything below that is underweight.
Interactive tool
Anorexic BMI Calculator
Enter your own values, then compare the result with the examples below.
Results
Minimum Healthy Weight by Height
| Height | Minimum Healthy Weight | Top of Healthy Range |
|---|---|---|
| 5'0" | 94.7 lb | 127.5 lb |
| 5'2" | 101.1 lb | 136.1 lb |
| 5'4" | 107.8 lb | 145.1 lb |
| 5'5" | 111.2 lb | 149.6 lb |
| 5'7" | 118.1 lb | 159.0 lb |
| 5'9" | 125.3 lb | 168.6 lb |
| 5'10" | 128.9 lb | 173.5 lb |
| 6'0" | 136.4 lb | 183.6 lb |
How Far Below the Line Matters
Being slightly under the minimum lands you in mild thinness (BMI 17-18.49). Dropping to a BMI under 17 is moderate thinness, and under 16 is severe thinness, which the WHO classifies as a critical risk. At 5'4", for instance, 107 lb is just underweight, while 96 lb would be moderate thinness.
Next Steps
Use the calculator above for your exact BMI and healthy range. If your result is in a thinness category, consider talking with a doctor or registered dietitian — this tool is for awareness, not diagnosis.
Frequently Asked Questions
What weight is too skinny for 5'7"?
Below about 118 lb at 5 foot 7, BMI falls under 18.5, which is underweight. Around 111 lb the reading drops into moderate thinness.
Can I be underweight even if I feel fine?
Yes. BMI is a screening measure, and some people feel well at low weights, but chronic underweight status is linked to bone loss, anemia, and weakened immunity over time.
Does this rule work for men and women?
Yes. The 18.5 BMI threshold is the same for both sexes, since BMI already adjusts for height.
How do I gain weight healthily?
Add calorie-dense, nutrient-rich foods and consider strength training to build lean mass. A dietitian can build a plan matched to your needs.