Body Fat Percentage Calculator
Calculate your body fat percentage using the U.S. Navy method. All you need is a tape measure!
Calculate Your Body Fat %
What Is Body Fat Percentage?
Body fat percentage measures what portion of your total body weight is actually fat tissue. Unlike BMI, it distinguishes between muscle, bone, water, and fat - giving you a far more accurate picture of your overall health and fitness level.
Body Fat Categories
The U.S. Navy Method
This calculator uses the U.S. Navy body fat formula, developed by the U.S. Navy for fitness assessments. It uses simple tape measurements of your neck, waist, and (for women) hips to estimate body fat with surprising accuracy - typically within 3-4% of more expensive methods.
How to Measure Correctly
Neck: Measure at the narrowest point, just below the Adam's apple. Keep tape level and don't flex your neck muscles.
Waist: Men measure at navel level. Women measure at the natural waist (narrowest point between ribs and hips).
Hips (women only): Measure at the widest point of your buttocks with feet together.
⚠️ For the most accurate results, use more advanced methods like DEXA scans or hydrostatic weighing. Learn more about body composition
Why Body Fat Percentage Matters More Than BMI
BMI has a major flaw: it can't tell the difference between muscle and fat. Two people with the same BMI can have completely different body compositions - one might be muscular and lean, the other might have excess body fat.
Body fat percentage tells you what portion of your total body weight is actually fat. This gives you a much better picture of your health because:
- It identifies "skinny fat": Someone with a normal BMI but high body fat percentage is at risk for metabolic diseases
- It works for athletes: Muscular people often show as "overweight" on BMI but have healthy or low body fat
- It tracks real progress: You could lose fat and gain muscle without the scale changing - body fat percentage catches this
- It's more accurate for health risk: Research links body fat percentage to disease risk more closely than BMI
Body Fat Percentage Categories
For Men
| Category | Body Fat % | Description |
|---|---|---|
| Essential Fat | 2-5% | Minimum needed for survival. Only seen in bodybuilders during competition. |
| Athletes | 6-13% | Lean, athletic physique with visible muscle definition. Hard to maintain. |
| Fitness | 14-17% | Fit appearance, some muscle definition. Healthy and sustainable. |
| Average | 18-24% | Typical range for healthy men. Some softness but generally healthy. |
| Overweight | 25-31% | Excess body fat. Consider lifestyle changes. |
| Obese | 32%+ | High body fat with significant health risks. |
For Women
| Category | Body Fat % | Description |
|---|---|---|
| Essential Fat | 10-13% | Minimum needed for survival. Can affect hormones and menstruation. |
| Athletes | 14-20% | Lean, athletic physique. Common in serious athletes and fitness competitors. |
| Fitness | 21-24% | Fit and toned appearance. Healthy and sustainable for most women. |
| Average | 25-31% | Typical healthy range for women. Supports normal hormone function. |
| Overweight | 32-39% | Excess body fat. Consider lifestyle changes. |
| Obese | 40%+ | High body fat with significant health risks. |
Why women have higher body fat: Women naturally carry more essential fat for reproductive function and hormone production. A body fat percentage that's healthy for a man would be dangerously low for a woman.
How to Take Accurate Measurements
The accuracy of this calculator depends on how precisely you measure. Here's how to get it right:
General Tips
- Use a flexible tape measure (cloth or plastic)
- Measure on bare skin or thin clothing
- Keep the tape level and snug (not tight)
- Take each measurement 2-3 times and use the average
- Measure at the same time of day for consistency
Height
Stand straight against a wall, heels together. Measure from floor to the top of your head.
Neck
Measure at the narrowest point of your neck, usually just below the Adam's apple (larynx). Keep your head level and look straight ahead. For men, this is typically about 1 inch below the larynx.
Waist
- Men: Measure at navel (belly button) level
- Women: Measure at the narrowest point, usually about 1 inch above the navel
Stand relaxed, don't suck in your stomach. Measure after exhaling normally.
Hips (Women Only)
Stand with feet together. Measure at the widest part of your hips/buttocks, keeping the tape level all the way around.
About the U.S. Navy Method
This calculator uses the U.S. Navy body fat formula, developed for assessing military fitness. It's one of the most practical methods because:
- Requires only a tape measure (no expensive equipment)
- Reasonably accurate (within 3-4% of more sophisticated methods)
- Easy to perform at home
- Validated on diverse populations
The Formulas
For Men:
Body Fat % = 495 ÷ (1.0324 - 0.19077 × log₁₀(waist - neck) + 0.15456 × log₁₀(height)) - 450
For Women:
Body Fat % = 495 ÷ (1.29579 - 0.35004 × log₁₀(waist + hip - neck) + 0.22100 × log₁₀(height)) - 450
Accuracy note: This method is typically accurate within ±3-4% compared to DEXA scans. It may be less accurate for very lean or very obese individuals, and for those with unusual body proportions.
Other Ways to Measure Body Fat
The Navy method is convenient, but there are other options:
More Accurate Methods
- DEXA Scan (Gold Standard): Uses X-rays to measure fat, muscle, and bone. Very accurate (±1-2%) but expensive ($75-150 per scan)
- Hydrostatic Weighing: Underwater weighing. Very accurate but requires special equipment
- Bod Pod: Air displacement measurement. Accurate and quick, available at some gyms and clinics
Less Accurate but Convenient
- Bioelectrical Impedance (BIA): Found in smart scales. Convenient but can be ±5-8% off depending on hydration
- Skinfold Calipers: Pinch and measure fat at several sites. Accuracy depends heavily on the person measuring
- Visual Estimation: Compare yourself to body fat percentage photos. Rough but free and instant
How to Lower Your Body Fat Percentage
Want to get leaner? Here's what actually works:
Nutrition (Most Important)
- Create a moderate calorie deficit: 300-500 calories below maintenance. Too aggressive leads to muscle loss
- Eat enough protein: 0.7-1g per pound of body weight helps preserve muscle while losing fat
- Focus on whole foods: Vegetables, lean proteins, whole grains keep you full on fewer calories
- Limit processed foods and added sugars: Easy to overeat, low satiety
Exercise
- Strength training: Essential for maintaining muscle while losing fat. 2-4 sessions per week
- Cardio: Helps create calorie deficit. Mix of moderate and high-intensity works best
- Stay active: Non-exercise activity (walking, stairs) burns more calories than you think
Lifestyle
- Sleep 7-9 hours: Poor sleep increases hunger hormones and makes fat loss harder
- Manage stress: Chronic stress raises cortisol, which promotes fat storage
- Be patient: Healthy fat loss is 0.5-1% body fat per month, not per week
Frequently Asked Questions
How accurate is this calculator?
The Navy method is typically accurate within ±3-4% of DEXA scans. Your result might be a bit higher or lower than your true body fat percentage, but it's good for tracking changes over time.
Why is my result different from my smart scale?
Smart scales use bioelectrical impedance, which is highly affected by hydration, food intake, and when you last exercised. The Navy method is often more consistent, though both have their limitations.
What's a healthy body fat percentage to aim for?
For most people: 14-24% for men, 21-31% for women. Athletes and fitness enthusiasts often aim lower, but going too low can affect hormones and energy levels. Find a level that's sustainable for your lifestyle.
How often should I measure my body fat?
Every 2-4 weeks is reasonable if you're actively trying to change your body composition. More frequent measurements will just show random fluctuations from measurement error and hydration changes.
Can I have low body fat but still be unhealthy?
Yes. Very low body fat can cause hormonal problems, immune suppression, and nutritional deficiencies. For women especially, too-low body fat can cause amenorrhea (loss of menstruation) and bone density issues.