BMI Result: 5ft 7in, 91 lbs (BMI 14.3) - Female
According to CDC and WHO standards, a BMI of 14.3 is classified as Underweight.
A female who is 5ft 7in tall and weighs 91lbs has a BMI of 14.3, 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 7in: 118 lbs – 159 lbs
Metric: 170.2 cm, 41.3 kg
📏 Healthy waist circumference for your height: 30" – 35" (below 35" for female)
So you're 5ft 7in and weigh 91lbs. Your BMI is 14.3, 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 26.8 lbs would bring your BMI to 18.5, the start of the next category.
⬆️ Gaining approximately 26.8 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 65 and older, BMI targets shift. Clinical guidelines (ESPEN, NIH) often recommend a slightly higher BMI range (around 23–26) for seniors to protect against bone loss and muscle decline. At 66 years old, a woman at 5ft 7in and 91lbs has a BMI of 14.3.
Your BMI of 14.3 is within the standard range but sits near the lower end. Maintaining muscle mass through protein intake and light resistance training is particularly important at this age.
👉 Use our Senior BMI Calculator for age-stratified recommendations.
👉 Check our Asian BMI Calculator for ethnicity-specific guidelines (if applicable).
Health Analysis
Recommendations
General Health
A BMI of 14.3 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.
Frequently Asked Questions
Am I at a healthy weight at 5ft 7in and 91lbs?
What health risks are associated with a BMI of 14.3 for a 5ft 7in woman?
How do I calculate my BMI at 5ft 7in and 91lbs?
How common is a BMI of 14.3 for a 5ft 7in woman?
Related Tools & Articles
💡 About this calculation: BMI = (91 × 703) ÷ (67 × 67) = 14.3 | Metric: 170.2 cm, 41.3 kg
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Published: 2026-09-07