Body Fat Calculator
Estimate your body fat percentage using the accurate US Navy circumference method.
About Body Fat %
The US Navy method estimates body fat from waist, neck, and (for women) hip circumferences. Accuracy is ±3% compared to DEXA scans — no expensive equipment needed.
Accuracy ±3–4 percentage points vs. DEXA scan for most adults. Accuracy is best in the 10–35% body fat range. Very lean individuals (under 10%) and those with unusual fat distribution may see larger errors. Take all circumference measurements three times and use the average; a flexible tape measure at the narrowest/widest point gives the most consistent results.
Body Fat Categories
| Category | Men | Women |
|---|---|---|
| Essential Fat | <5% | <14% |
| Athlete | 6–13% | 14–20% |
| Fitness | 14–17% | 21–24% |
| Average | 18–24% | 25–31% |
| Obese | >25% | >32% |
Healthy body fat: 14–24% (women), 6–17% (men)
What to do with your result
- If in the obese category: set a calorie deficit using the TDEE Calculator and aim for 0.5–1 kg/week fat loss. Prioritize preserving lean mass with adequate protein (at least 1.6 g/kg body weight).
- If in the average category: add 2–3 strength training sessions per week and ensure your protein intake supports muscle building. Check your Lean Body Mass to track your muscle-to-fat ratio.
- Recheck your body fat every 6–8 weeks. Measure under the same conditions (morning, fasted, same tape measure) to ensure comparability.
- Cross-reference with your Waist-to-Hip Ratio and Waist-to-Height Ratio to assess cardiovascular risk from abdominal fat distribution, not just total body fat.
Frequently Asked Questions
How accurate is the US Navy body fat method?
The US Navy circumference method is accurate to within ±3–4 percentage points compared to DEXA scans for most adults. It works best for body fat levels between 10–35%. Very lean people and those with unusual fat distribution may see larger errors. Averaging three measurements and using a flexible tape measure at the correct anatomical locations improves accuracy.
What should I do after getting my body fat result?
If you are in the obese or high-average range, calculate your TDEE and create a 300–500 kcal/day deficit. Combine diet with resistance training to preserve lean mass. If you are in the fitness or athlete range, focus on maintaining your lean mass through adequate protein and progressive training. Recheck every 6–8 weeks to monitor progress.
How often should I remeasure?
Measure every 6–8 weeks when actively trying to change body composition. Avoid daily measurements — hydration fluctuations can change circumferences by 1–2 cm, creating false readings. Always measure in the morning, before eating, after using the bathroom, in a relaxed state (not after exercise or a large meal).
Is this method accurate for athletes?
The US Navy method is reasonably accurate for athletic populations with typical body proportions. Athletes with very large necks (strength athletes) or very small waists relative to body weight may see skewed results. For competitive athletes, DEXA or hydrostatic weighing every 3–6 months provides more precise tracking for performance optimization.
What does my body fat percentage mean for my health?
Body fat above 25% (men) or 32% (women) is associated with increased risk of type 2 diabetes, cardiovascular disease, and metabolic syndrome. The fitness range (14–17% for men, 21–24% for women) is associated with good metabolic health markers. Essential fat levels (below 5% for men, below 14% for women) are the minimum needed for organ protection and hormone production — going below these thresholds is dangerous and requires medical supervision.
This calculator is for educational purposes only. Consult a qualified healthcare professional for medical advice.