Body Fat Calculator
Estimate your body fat percentage, fat mass, and lean mass using two proven methods — the U.S. Navy circumference formula and a BMI-based estimate. Supports US, metric, and stone units.
Body Fat Calculator
US Navy method + BMI estimate
Body Fat Percentage
13.8%
Fitness- Fat Mass
- 22.1 lbs
- Lean Mass
- 137.9 lbs
- Ideal Range
- 14–17%
📊 Body Fat Scale
| Essential Fat | 2–5% | |
| Athlete | 6–13% | |
| Fitness | 14–17% | ← You |
| Average | 18–24% | |
| Obese | 25–∞% |
🥧 Body Composition Breakdown
Medical Disclaimer: This calculator provides estimates only. Body fat measurements can vary based on hydration, measurement technique, and individual body composition. Always consult a healthcare professional for medical advice. Do not use results for diagnostic purposes.
How Body Fat is Calculated
This calculator offers two ways to estimate body fat percentage: the U.S. Navy circumference method, which uses a tape measure and is widely used by military and fitness programs, and a simpler BMI-based estimate for when you don't have measuring tape handy. For overall weight status, also see our BMI calculator and ideal weight calculator. If you're specifically after the official military standard with pass/fail thresholds by age, see our Army Body Fat Calculator.
🧮 Calculation Methods Used
U.S. Navy Circumference Method
Male: 86.010×log10(waist−neck) − 70.041×log10(height) + 36.76Female: 163.205×log10(waist+hip−neck) − 97.684×log10(height) − 78.387Accuracy: ±3-4%
BMI-Based Estimate
Male: (1.20×BMI) + (0.23×age) − 16.2Female: (1.20×BMI) + (0.23×age) − 5.4Accuracy: ±5-6%
📋 Body Fat Categories (ACE)
| Category | Men | Women |
|---|---|---|
| Essential fat | 2-5% | 10-13% |
| Athlete | 6-13% | 14-20% |
| Fitness | 14-17% | 21-24% |
| Average | 18-24% | 25-31% |
| Obese | 25%+ | 32%+ |
🔻 How to Reduce Body Fat
- Calorie deficit: a ~500 cal/day deficit produces roughly 1 lb/week of fat loss — see our calorie calculator
- Strength training: preserves lean mass while losing fat
- Cardio: efficient for burning calories and improving cardiovascular fitness
- Protein: 0.7-1 g per lb of body weight protects muscle during a deficit
- Sleep & stress: poor sleep and chronic cortisol both promote fat storage
⚖️ Body Fat vs BMI
BMI measures weight relative to height — it can't distinguish muscle from fat. A muscular athlete can have a “high” BMI but low body fat. Body fat % directly measures the proportion of fat tissue, a much better indicator of health risk. Use both together for a complete picture.
📏 How to Measure Correctly
- Neck: just below the larynx (Adam's apple), perpendicular to the neck axis
- Waist: at navel level, exhaled normally, not sucked in
- Hip (women): at the widest point around the buttocks
- Use a flexible tape measure, not a ruler
- Take 2-3 readings and use the average
— FAQ