BMI Result: 5ft 9in, 105 lbs (BMI 15.5) - Male

According to CDC and WHO standards, a BMI of 15.5 is classified as Underweight.

Quick answer: A 5ft 9in male weighing 105 lbs has a BMI of 15.5, classified as Underweight by CDC and WHO standards. The healthy weight range for this height is approximately 125–169 lbs.

A male 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.

15.5
Underweight
⚠️ BMI is a screening tool, not a diagnostic. It does not measure body fat directly. Learn more about how BMI is used.
Underweight Normal Overweight Obese
CategoryBMI 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: 35" – 40" (below 40" for male)

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.

Adult BMI classification: CDC & WHO standard (effective 1998-present).

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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.

Source: CDC Adult BMI Guidelines (2024)

What This Means for Your Height

For men of average height, BMI is a reliable screening tool. The CDC recommends keeping waist circumference below 40 inches to minimize health risks.

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 men keep waist circumference below 40 inches. A waist-to-height ratio below 0.5 is also associated with lower health risks.

Source: CDC Adult BMI Guidelines (2024)

Age Context

For adults 45-64, metabolic health becomes increasingly important. At 47 years old, a man at 5ft 9in and 105lbs has a BMI of 15.5, 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.

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Health Analysis

A BMI of 15.5 for a male with height 5ft 9in and weight 105lbs falls into the Underweight category.

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 males stay under 40 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

Physical Activity

For a man at 5ft 9in, focus on strength training 3-4 times per week to build muscle mass. Compound exercises like squats, deadlifts, and bench press are most effective. The CDC recommends consulting a healthcare provider before starting any new exercise program.

Diet & Nutrition

At 5ft 9in and 105lbs, a BMI of 15.5 indicates underweight. For men of this height, the CDC recommends a healthy weight range of 125-168lbs. Focus on protein-rich foods and resistance training to build muscle mass.

Always consult a healthcare provider for personalized medical advice.

Frequently Asked Questions

How do I calculate my BMI at 5ft 9in and 105lbs?
BMI is calculated as weight (lbs) × 703 ÷ height (in)². For a 5ft 9in man at 105lbs, the calculation is 105 × 703 ÷ 69² = 15.5, which is Underweight.
How does a BMI of 15.5 affect health for a 5ft 9in man?
At 5ft 9in with a BMI of 15.5 (Underweight), the underweight range is associated with increased risk of bone density loss and immune function decline. Maintaining a healthy lifestyle is key to overall well-being.
How common is a BMI of 15.5 for a 5ft 9in man?
According to CDC data, about 1.5% of men have a BMI in the Underweight category. At 5ft 9in and 105lbs, your BMI of 15.5 is within this range.
What else should I track besides BMI for a 5ft 9in man?
In addition to BMI, waist circumference and body composition give a clearer picture of health. For a man at 5ft 9in, keeping waist size below 40 inches is an important goal supported by CDC research.

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Related Tools & Articles

💡 About this calculation: BMI = (105 × 703) ÷ (69 × 69) = 15.5 | Metric: 175.3 cm, 47.6 kg

📖 Recommended reading:

BMI data sourced from CDC and WHO guidelines. This content is informational only. Please consult a healthcare professional for any health decisions.

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

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