BMI Result: 5ft 5in, 100 lbs (BMI 16.6) - Female
According to CDC and WHO standards, a BMI of 16.6 is classified as Underweight.
A female who is 5ft 5in tall and weighs 100lbs has a BMI of 16.6, which falls into the Underweight category used by the CDC and WHO for adults.
| Category | BMI Range |
|---|---|
| Underweight | < 18.5 |
| Underweight | < 18.5 |
| Obese | ≥ 30 |
Healthy weight range for 5ft 5in: 111 lbs – 150 lbs
Metric: 165.1 cm, 45.4 kg
📏 Healthy waist circumference for your height: 30" – 35" (below 35" for female)
So you're 5ft 5in and weigh 100lbs. Your BMI is 16.6, which falls into the Underweight category according to CDC and WHO standards. Let's break down what this means for your health.
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Change your height or weight to see how your BMI changes.
Understanding Your BMI
A BMI below 18.5 may indicate nutritional insufficiency. According to the CDC, this range is associated with increased risk of bone density loss and immune function decline. Consulting a healthcare provider is recommended for a thorough nutritional assessment.
What This Means for Your Height
For women of average height, BMI is a reliable screening tool. Pair it with waist circumference for a more complete health picture.
Weight & Threshold
Gaining approximately 11.4 lbs would bring your BMI to 18.5, the start of the next category.
⬆️ Gaining approximately 11.4 lbs would put you in the Normal BMI range.
Waist & Health
The CDC recommends that non-pregnant women keep waist circumference below 35 inches. A waist-to-height ratio below 0.5 is also associated with lower health risks.
Age Context
For adults 45-64, metabolic health becomes increasingly important. At 52 years old, a woman at 5ft 5in and 100lbs has a BMI of 16.6, which falls into the Underweight category.
For adults in this age range, maintaining stable weight and regular physical activity is key to preserving metabolic health.
👉 Calculate your Body Fat Percentage for a more complete health assessment.
👉 Try our Athlete BMI Calculator if you have higher muscle mass.
Health Analysis
Recommendations
General Health
A BMI of 16.6 is below the CDC and WHO healthy range of 18.5-24.9. This may indicate nutritional insufficiency. Consulting a healthcare provider is recommended for a thorough nutritional assessment.
Monitoring
In addition to BMI, pay attention to waist circumference. The CDC recommends females stay under 35 inches. Regular tracking of your measurements over time provides the most useful insight into your health trends.
Next Steps
If you're concerned about your weight or body composition, a healthcare provider can offer personalized guidance based on your full health profile.
Personalized Notes
Goals
For a woman at 5ft 5in, the CDC recommends a healthy weight range of 111-149lbs. At 100lbs, you're below this range. Consider setting a goal to gain 5-10% of your current weight over the next 3-6 months.
Monitoring
At 5ft 5in, track your weight weekly. The healthy weight range for women at this height is 111-149lbs. Monitor waist circumference too—the CDC recommends below 35 inches.
Frequently Asked Questions
How does a BMI of 16.6 affect health for a 5ft 5in woman?
How common is a BMI of 16.6 for a 5ft 5in woman?
Is 100lbs overweight for a 5ft 5in woman?
What else should I track besides BMI for a 5ft 5in woman?
Related Tools & Articles
💡 About this calculation: BMI = (100 × 703) ÷ (65 × 65) = 16.6 | Metric: 165.1 cm, 45.4 kg
📖 Recommended reading:
Editorial Review: This page was generated by the BMI Calculator Web Editorial Team and reviewed at template and content-pool level for accuracy and guideline alignment by Dr. Sarah K. Johnson, PhD, RD. All content is aligned with current WHO, CDC, and NIH guidelines.
Published: 2026-07-31