Calculate your body fat percentage quickly and accurately using our free online calculator. Choose from multiple validated methods including US Navy, US Army, and BMI-based calculations.
Understanding your body composition is more important than just knowing your weight. Body fat percentage reveals how much of your weight comes from fat versus lean muscle mass, giving you a clearer picture of your health and fitness level.
Body Fat Percentage Calculator
Multi-Method Body Composition Analysis
All calculations are performed in your browser. No measurements are stored or transmitted.
Calculate Your Body Fat Percentage
Enter your measurements below. The US Navy method requires waist, neck, and hip (for females) circumference measurements. The BMI-based method uses height, weight, age, and sex.
Understanding Body Fat Percentage
Body fat percentage is the proportion of your total body weight that consists of fat tissue. Unlike BMI, which only considers height and weight, body fat percentage distinguishes between fat mass and lean mass (muscle, bone, water, organs).
Why Body Fat Matters More Than Weight
- Two people with the same weight can have very different body compositions; a muscular athlete may weigh the same as a sedentary person but have much lower body fat
- BMI limitations: BMI can misclassify muscular individuals as overweight
- Health correlation: Body fat percentage is a better predictor of metabolic health than weight or BMI alone
- Visceral fat (fat around organs) is a particularly important health risk factor, even in people with "normal" BMI
Essential vs. Storage Fat
Essential fat is necessary for normal physiological function. Men require approximately 2-5% essential fat; women require 10-13% (due to reproductive and hormonal needs). Storage fat accumulates beneath the skin (subcutaneous) and around organs (visceral). Some storage fat provides insulation and energy reserves, but excess increases health risks.
Body Fat Measurement Methods
US Navy Method (Used in This Calculator)
Developed by the US Navy for fitness assessments. Uses circumference measurements of the waist, neck, and hip (for females) along with height. Accuracy is within 3-4% of more precise methods for most people. Best for tracking changes over time.
BMI-Based Estimation (Used in This Calculator)
Uses the Deurenberg formula to estimate body fat from BMI, age, and sex. Less accurate than circumference methods but requires only height and weight. Better suited as a screening tool than for precise measurement.
More Accurate Methods (Clinical)
- DEXA Scan: Gold standard. Uses dual-energy X-ray absorptiometry. Accuracy +/- 1-2%. Available at clinics and hospitals.
- Hydrostatic Weighing: Underwater weighing. Very accurate (+/- 1.5%). Less convenient.
- Bod Pod: Air displacement plethysmography. Accurate (+/- 2-3%). Available at some fitness centers.
- Skinfold Calipers: Requires trained technician. Accuracy depends on technique (+/- 3-4%).
- Bioelectrical Impedance: Found in smart scales. Convenient but affected by hydration status (+/- 3-8%).
Body Fat Categories
For Males
- Essential Fat: 2-5% - Minimum needed for survival. Not a healthy target for the general population.
- Athletes: 6-13% - Common in competitive athletes. Very lean, visible muscle definition.
- Fitness: 14-17% - Active individuals. Some muscle definition visible.
- Average: 18-24% - Typical healthy adult male. Acceptable body composition.
- Obese: 25%+ - Associated with increased health risks.
For Females
- Essential Fat: 10-13% - Minimum needed for hormonal and reproductive function.
- Athletes: 14-20% - Common in competitive female athletes.
- Fitness: 21-24% - Active, fit women.
- Average: 25-31% - Typical healthy adult female.
- Obese: 32%+ - Associated with increased health risks.
Important Note
Healthy body fat percentages differ significantly by sex due to biological differences. Women naturally carry more essential fat for reproductive and hormonal functions. These categories are guidelines; individual health should be assessed holistically, including blood markers, fitness level, and overall well-being.
Evidence-Based Strategies for Reducing Body Fat
Nutrition
- Moderate caloric deficit: Aim for 300-500 calories below maintenance for sustainable fat loss
- High protein intake: 0.7-1.0 g per pound of body weight to preserve muscle mass
- Whole foods focus: Prioritize vegetables, lean proteins, whole grains, and healthy fats
- Avoid crash diets: Extreme restriction leads to muscle loss and metabolic adaptation
Exercise
- Resistance training: Critical for preserving and building muscle during fat loss
- Cardio: Supports caloric deficit; mix of moderate and high-intensity
- NEAT: Non-exercise activity thermogenesis (walking, stairs, standing) adds up significantly
- Consistency over intensity: Sustainable habits outperform short-term extreme programs
Lifestyle Factors
- Sleep: Poor sleep increases hunger hormones and promotes fat storage
- Stress management: Chronic stress elevates cortisol, which promotes visceral fat accumulation
- Patience: Healthy fat loss is 0.5-1% of body weight per week
Frequently Asked Questions
The US Navy method is accurate to within 3-4% of DEXA scan results for most people. The BMI-based method is less precise (4-5%). Both methods are most useful for tracking trends over time rather than determining an exact percentage. For precise measurement, consider a DEXA scan or Bod Pod assessment.
BMI only considers height and weight, while body fat percentage considers body composition. A muscular person may have a high BMI (classified as "overweight") but a healthy body fat percentage. Conversely, someone with a "normal" BMI can have an elevated body fat percentage if they have low muscle mass. This is why body fat percentage is generally considered a better indicator of health.
Healthy ranges differ by sex and age. For males, 10-20% is generally considered healthy, with 14-17% being the "fitness" range. For females, 18-28% is healthy, with 21-24% being the "fitness" range. Essential fat minimums are 2-5% for males and 10-13% for females. Going below essential fat levels is dangerous for health.
For waist: Stand relaxed (don't suck in your stomach). Men should measure at navel level; women at the narrowest point of the torso. For neck: Measure just below the larynx (Adam's apple), keeping the tape level. For hips (females): Measure at the widest point of the buttocks. Use a flexible tape measure snug against the skin but not compressing it. Measure 2-3 times and take the average.
Women naturally carry more body fat due to biological differences related to reproduction and hormonal function. Estrogen promotes fat storage in the breasts, hips, and thighs. Women require higher essential fat (10-13% vs. 2-5% for men) for normal menstrual function and overall health. Dropping below essential fat levels can cause hormonal disruption and amenorrhea in women.
Yes, this is called body recomposition. By combining resistance training with adequate protein intake, you can gain muscle while losing fat. Since muscle is denser than fat, you may maintain or even slightly gain weight while your body fat percentage decreases and your measurements change. This is why tracking body fat percentage and measurements is more informative than tracking weight alone.
⚠ Important Disclaimer
This body fat calculator provides estimates based on mathematical formulas and should not be considered a medical diagnosis. For precise body composition analysis, consult a healthcare provider or certified fitness professional. Body fat estimates should be part of a comprehensive health assessment, not the sole indicator of health status.
Clinical References
- Hodgdon, J. A., & Beckett, M. B. (1984). Prediction of percent body fat for U.S. Navy men and women from body circumferences and height. Naval Health Research Center, Report No. 84-29.
- Deurenberg, P., Weststrate, J. A., & Seidell, J. C. (1991). Body mass index as a measure of body fatness: age- and sex-specific prediction formulas. British Journal of Nutrition, 65(2), 105-114.
- American Council on Exercise (ACE). Body Fat Percentage Norms.
- Gallagher, D., et al. (2000). Healthy percentage body fat ranges: an approach for developing guidelines based on body mass index. American Journal of Clinical Nutrition, 72(3), 694-701.
- National Institutes of Health (NIH). Assessing Your Weight and Health Risk.