Navy Body Fat Calculator (Hodgdon-Beckett)
Estimate body fat percentage with the official U.S. Navy circumference method from height, neck, waist and hip measurements, with accuracy limits and healthy-range categories.
Results
- Estimated body fat
- 17%
- Hodgdon-Beckett (U.S. Navy) estimate
- Category
- Fitness
- General population ranges (ACE-style categories)
- Military standard (age 22-29)
- 23% max
- You are within the standard
U.S. Navy maximum body-fat standards by age
| Age | Men (max) | Women (max) |
|---|---|---|
| 17-21 | 22% | 33% |
| 22-29 | 23% | 34% |
| 30-39 | 24% | 35% |
| 40+ | 26% | 36% |
General body-fat categories
| Category | Men | Women |
|---|---|---|
| Essential fat | 2-5% | 10-13% |
| Athletes | 6-13% | 14-20% |
| Fitness | 14-17% | 21-24% |
| Acceptable | 18-24% | 25-31% |
| Above acceptable | 25%+ | 32%+ |
How it works & limitations
The Hodgdon-Beckett equations
Men: 86.010 x log10(waist - neck) - 70.041 x log10(height) + 36.76 Women: 163.205 x log10(waist + hip - neck) - 97.684 x log10(height) - 78.387 All measurements are converted to inches before calculation.
Accuracy
The Navy circumference method agrees with hydrostatic weighing within roughly 3-4% for most people. It tends to overestimate in very lean individuals and underestimate at higher body-fat levels. For tracking, measure at the same time of day with the same tape tension.
Military standards are compliance, not health
The age-based maximums are military accession/retention standards. Meeting or missing them is not a health diagnosis - interpret body fat alongside performance, waist-to-height ratio and clinical markers.
Sources
Last updated 2026-08-13
- Hodgdon, J. A., & Beckett, M. B. (1984). Prediction of percent body fat for U.S. Navy men from body circumferences and height. Report No. 84-29, Naval Health Research Center, San Diego, CA.
- U.S. Department of Defense. Body composition standards for military service members.
An estimate, not a medical measurement. DEXA or hydrostatic weighing is more accurate when body-composition decisions matter.
Frequently asked questions
How accurate is the Navy method?
The Hodgdon-Beckett circumference method is generally accurate to within about 3-4% of hydrostatic weighing or DEXA for most people. It tends to overestimate in very lean individuals and underestimate at higher body-fat levels.
Where exactly do I measure waist and neck?
Neck: just below the Adam's apple at the narrowest point. Waist (men): at the navel, standing relaxed. Waist (women): at the narrowest point of the torso. Hip (women): at the widest point of the hips and buttocks. Measure with a tape parallel to the floor, without pulling tight.