Navy Body Fat Calculator (Hodgdon & Beckett)

Body fat percentage is a crucial metric in assessing overall health and fitness. There are various methods available for estimating body fat, each with its own strengths and limitations. One such method is the Navy Hodgdon-Beckett method, commonly known as the Navy Body Fat Formula. Developed by the U.S. Navy, this method provides a practical and reliable way to estimate body fat percentage, especially for military personnel.

Important Note: The Navy Body fat formula is often confused with the Navy Hodgdon Weight-Height Regression Body fat formula which is also available.

Male

Female

Height in

feet & inchcentimeter

Measurement in

inchcentimeter

Your Body Fat Percentage Results

17.46%
Body Fat (Athletes)

> 32.0 Obese
25.0-32.0 Average
21.0-25.0 Fitness
14.0-21.0 Athletes
< 14.0 Essential fat

The Navy Body Fat Formula

The Navy Body Fat Formula is based on a simple linear regression model that takes into account the relationship between body circumference measurements and body fat percentage. The formula requires three measurements:

for Males - height, neck circumference, and abdomen circumference
for Females - height, neck circumference, waist circumference and hip circumference

5' 5"

Height

14.0"

Neck

28.0"

Waist

33.0"

Hip

The formula utilizes logarithmic functions to estimate the body fat percentage from these measurements. First it creates an output called density which will then get converted to Body Fat percentage.

Density (male) = -0.19077 \cdot \log_{10}(\text{abdomenBellyButtonInCm} - \text{neckInCm}) \\+ 0.15456 \cdot \log_{10}(\text{heightInCm}) + 1.0324

Density (female) = -0.35004 \cdot \log_{10}(\text{waistInCm} + \text{hipInCm} - \text{neckInCm}) \\+ 0.221 \cdot \log_{10}(\text{heightInCm}) + 1.29579

Body Fat = 100.0 \times \left(\frac{4.95}{\text{density}} - 4.5\right)

Side note: There are a couple of variations of this formula "floating around" the internet but all with the same result. The original papers sourced below are contain references referring to the formulas with their density variables. Other calculators may combine this into a single formula with slightly different constants.

This Body Fat formula is slightly better suited for more active individuals and provides a better estimate for Body fat.

Based On	Weight	Tape Measure	Skinfold
Measurement Complexity	Very Easy	Easy	Difficult
Accuracy/Precision	Low	Medium	High
Best Suited For	Non-Active Person	Active Enthusiast	Athlete

Understanding the Results

Healthy Ranges: Body fat percentage varies based on factors such as age and gender. For men, a body fat percentage between 6-24% is considered normal, while for women, the normal range is between 16-30%.

Interpretation: A higher body fat percentage may indicate a higher risk of obesity-related health issues, while too low a percentage may pose health risks as well.

Considerations and Limitations

Population-Specific: The Navy Body Fat Formula was initially developed for military personnel and might not be as accurate for the general population.
Alternative Methods: While the Navy method is convenient, there are other accurate methods like Dual-Energy X-ray Absorptiometry (DEXA) and hydrostatic weighing. These methods might be more precise but can be less practical due to cost and accessibility.
Individual Variation: Body fat distribution varies among individuals, and this formula might not capture those differences accurately.

Conclusion

The Navy Hodgdon-Beckett Weight-Height Regression method offers a straightforward and accessible way to estimate body fat percentage. While it may not be as precise as some advanced techniques, it provides a useful tool for individuals looking to monitor their body composition. As with any method, it's essential to understand its limitations and consider consulting with a healthcare professional for a comprehensive assessment of your health and fitness.

Measurement Help

Neck

How to measure

Smallest measurement just below the adams apple
Tape measure should be sloping slightly downwards

Waist

Body Position

breathe out to "remove slack"
You may want to flex your ab muscles to help on finding a neutral mid section position

How to measure

Narrowest part of your mid section below rib cage and above top of the hip bone
Generally at or above the naval area, its possible that this location may "move" as you change body composition

Hip

Body Position

Standing on flat surface with feet slightly appart (generally right below your respective hip joint)

How to measure

largest measurement generally in the middle of your hip, ie the peak of your butt

Original Research Paper: "Hodgdon, J. A., & Beckett, M. B. (1984). Prediction of percent body fat for U.S. Navy men and women from body circumferences and height" This seminal research paper, published in the Naval Health Research Center Technical Report, outlines the development and validation of the Navy Body Fat Formula.
https://apps.dtic.mil/sti/citations/ADA143890

Original Research Paper: "Hodgdon, J. A., & Beckett, M. B. (1984). Prediction of Percent Body Fat for U.S. Navy Women from Body Circumferences and Height" This seminal research paper, published in the Naval Health Research Center Technical Report, outlines the development and validation of the Navy Body Fat Formula.
https://apps.dtic.mil/sti/citations/ADA146456

U.S. Department of Defense Instruction: "DoD Instruction 1308.3 - DoD Physical Fitness and Body Fat Programs Procedures." This official document sheds light on the military application of the Navy method, detailing its use in assessing body fat for U.S. military personnel.
https://apps.dtic.mil/sti/citations/ADA306887

Navy Body Fat Calculator (Hodgdon & Beckett)

The Navy Body Fat Formula

Understanding the Results

Considerations and Limitations

Conclusion

Measurement Help

Neck

Waist

Hip

Body Composition Calculators

New Calculators

Links

Support