U.S. Navy Method
The Navy body fat estimation uses tape measurements plus height:
- •Men: neck, waist
- •Women: neck, waist, hip
Density is inferred from circumference ratios, then body fat % is estimated from formulas (Siri or similar). No calipers or water tank needed — but accuracy is moderate.
Measurement Tips
| Tip | Why |
|---|---|
| Same time of day | Reduces bloat variance |
| Relaxed, not flexed | Consistent muscle tension |
| Parallel tape | Avoids skew |
| Measure 2–3×, average | Reduces error |
Poor half-inch errors on waist can swing the result noticeably.
Compared to Gold Standards
| Method | Accuracy | Access |
|---|---|---|
| DEXA | High | Clinic |
| Hydrostatic | High | Lab |
| Bod Pod | Good | Some gyms |
| Navy tape | OK for trends | Home |
Use Navy for tracking direction month to month — not absolute % for contest prep.
How to Use This Calculator
Enter sex, height, age, and measurements as prompted. Read estimated body fat % and interpret alongside photos, performance, and health markers.