🧍 Body Fat Percentage Calculator

Estimate body composition using the US Navy circumference method or optional YMCA skinfold data. Get lean mass insights and personalized body composition recommendations.

Measurements

Age

years

Gender

Height

Weight

Neck

Below Adam's apple

Waist

At navel level

Skinfold Sum (Optional)

Total of 3-site caliper measurements

Calculation Method

Results

📏

Body Fat (Navy)

Category: —

🧪

Body Fat (Skinfold)

—

Add caliper data

💪

Lean Body Mass

0 kg

Fat mass: 0 kg

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Target Range

—

Guidance

Classification	Body Fat %	Notes
Essential	—	Minimum for basic function
Athletic	—	Typical of athletes
Fitness	—	Healthy & sustainable
Average	—	Common population range
Obese	—	Higher health risk

Skinfold and Navy methods align closely.

💡 Recommendations

How It Works

Formulas

US Navy Method:
Male BF% = 495 / [1.0324 − 0.19077 log₁₀(waist − neck) + 0.15456 log₁₀(height)] − 450
Female BF% = 495 / [1.29579 − 0.35004 log₁₀(waist + hip − neck) + 0.22100 log₁₀(height)] − 450

YMCA Skinfold Method:
Male BF% = (0.1051 × ΣSF) + 2.585
Female BF% = (0.1548 × ΣSF) + 3.580

What is Body Fat Percentage?

Body fat percentage represents the proportion of your total weight that comes from fat mass versus lean mass (muscle, bones, organs, water). Unlike BMI, it directly accounts for body composition and provides a more accurate picture of health and fitness. The US Navy method uses circumference measurements, while the skinfold method uses caliper readings from specific body sites.

Example

Example: A 30-year-old male, 175 cm tall, 75 kg, with neck 38 cm and waist 82 cm has:
Navy BF%: ~18%
Lean Mass: ~61.5 kg
Fat Mass: ~13.5 kg
Category: Fitness (healthy range for males: 14-17%)

References & Sources

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US Navy Physical Readiness Program

Official documentation of the Navy circumference method for body composition assessment

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American Council on Exercise (ACE)

Body fat percentage guidelines and skinfold measurement protocols

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YMCA Fitness Testing and Assessment

Standardized skinfold measurement protocols and body composition assessment

Frequently Asked Questions

Which method is more accurate - Navy or Skinfold? ▼

The Navy method is more accessible (requires only a measuring tape) and works well for most people. Skinfold calipers can be more precise but require proper technique and consistent measurement sites. Using both methods and averaging gives the most reliable estimate.

What is a healthy body fat percentage? ▼

For males, 10-20% is generally considered healthy (fitness range: 14-17%). For females, 18-28% is healthy (fitness range: 21-24%). Athletes may have lower percentages, but going too low can affect hormones and health.

How often should I measure body fat percentage? ▼

Measure every 2-4 weeks at the same time of day (ideally morning) for consistency. Body fat changes slowly, so weekly measurements aren't necessary. Take multiple measurements each time and average them.

Why do the Navy and Skinfold methods give different results? ▼

Each method uses different body sites and formulas. Differences of 2-3% are normal. If they differ by more than 5%, double-check your measurements—especially tape tension for Navy and pinch technique for skinfolds.

What's the difference between lean mass and muscle mass? ▼

Lean mass includes everything except fat: muscles, bones, organs, water, and connective tissue. Muscle mass is just skeletal muscle. Our calculator estimates lean mass, which is typically 60-75% muscle depending on training status.