BMI Result: 5ft 9in, 105 lbs (BMI 15.5) - Female
According to CDC and WHO standards, a BMI of 15.5 is classified as Underweight.
A female who is 5ft 9in tall and weighs 105lbs has a BMI of 15.5, 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 9in: 125 lbs – 169 lbs
Metric: 175.3 cm, 47.6 kg
📏 Healthy waist circumference for your height: 30" – 35" (below 35" for female)
So you're 5ft 9in and weigh 105lbs. Your BMI is 15.5, which falls into the Underweight category according to CDC and WHO standards. Let's break down what this means for your health.
Adjust Your Numbers
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 20.3 lbs would bring your BMI to 18.5, the start of the next category.
⬆️ Gaining approximately 20.3 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
At ages 18-19, BMI interpretation transitions. This age range sits between pediatric percentiles and adult fixed cutoffs. A 18-year-old woman at 5ft 9in and 105lbs has a BMI of 15.5, which falls into the Underweight category under adult CDC/WHO standards.
👉 For younger individuals, visit our Teen BMI Calculator.
👉 Check your Healthy Weight Range for more context.
Health Analysis
Recommendations
General Health
A BMI of 15.5 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
Health Risks
With a BMI of 15.5 for a 5ft 9in woman, the underweight 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.
Monitoring
At 5ft 9in, track your weight weekly. The healthy weight range for women at this height is 125-168lbs. Monitor waist circumference too—the CDC recommends below 35 inches.
Frequently Asked Questions
Is 105lbs overweight for a 5ft 9in woman?
How common is a BMI of 15.5 for a 5ft 9in woman?
How does a BMI of 15.5 affect health for a 5ft 9in woman?
How do I calculate my BMI at 5ft 9in and 105lbs?
Related Tools & Articles
💡 About this calculation: BMI = (105 × 703) ÷ (69 × 69) = 15.5 | Metric: 175.3 cm, 47.6 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: 2026-08-20