BMI Result: 5ft 9in, 120 lbs (BMI 17.7) - Female
According to CDC and WHO standards, a BMI of 17.7 is classified as Underweight.
A female who is 5ft 9in tall and weighs 120lbs has a BMI of 17.7, 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, 54.4 kg
📏 Healthy waist circumference for your height: 30" – 35" (below 35" for female)
So you're 5ft 9in and weigh 120lbs. Your BMI is 17.7, 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 5.4 lbs would bring your BMI to 18.5, the start of the next category.
⬆️ Gaining approximately 5.4 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 46 years old, a woman at 5ft 9in and 120lbs has a BMI of 17.7, 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 17.7 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
Diet & Nutrition
At 5ft 9in and 120lbs, a BMI of 17.7 indicates underweight. For women of this height, the CDC recommends a healthy weight range of 125-168lbs. Consider nutrient-dense foods like nuts, avocados, and lean proteins to support healthy weight gain.
Health Risks
With a BMI of 17.7 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.
Frequently Asked Questions
Am I at a healthy weight at 5ft 9in and 120lbs?
What percentage of women have a BMI of 17.7 at 5ft 9in?
How do I calculate my BMI at 5ft 9in and 120lbs?
What else should I track besides BMI for a 5ft 9in woman?
Related Tools & Articles
💡 About this calculation: BMI = (120 × 703) ÷ (69 × 69) = 17.7 | Metric: 175.3 cm, 54.4 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: 2026-08-20