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±3% Accuracy Navy Method

Calculate Your Body Fat Percentage

Get professional-grade body composition analysis in 60 seconds using Navy, BMI or Skinfold methods

3 scientific methods Instant results 100% free

Choose Your Method

Select calculation method and enter measurements

Years (18-80)
Required for accuracy
Centimeters
Kilograms

Your Results

Your body fat analysis will appear here after calculation

--
Body Fat Percentage
--
-- kg
Fat Mass
-- kg
Lean Mass
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Category

Which Method Should You Use?

Navy Method

Uses tape measure to measure neck, waist (and hips for women). Most accurate for general population without special equipment.

±3% accuracy

BMI Method

Quick estimate using only height, weight and age. Less accurate for muscular individuals but fastest method.

±5-7% accuracy

Skinfold Method

Requires calipers to measure subcutaneous fat. Very accurate with proper technique and consistent measurement.

±3-5% accuracy

Healthy Body Fat Ranges

Men's Ranges

Essential Fat
2-5%
Athletes
6-13%
Fitness
14-17%
Average
18-24%
Obese
25%+

Women's Ranges

Essential Fat
10-13%
Athletes
14-20%
Fitness
21-24%
Average
25-31%
Obese
32%+

How the Body Fat Calculator Works

Understanding body composition measurement methods

The U.S. Navy Method

Our calculator uses the U.S. Navy circumference method, which estimates body fat percentage from waist, neck, and hip measurements. This formula was developed by military researchers and validated against DEXA scans and hydrostatic weighing.

The method works because fat distribution patterns correlate with total body fat. Larger waist relative to height indicates higher fat mass. Gender-specific formulas account for different fat storage patterns.

Accuracy Comparison:

  • DEXA Scan: ±1-2% (gold standard)
  • Hydrostatic: ±2-3% (highly accurate)
  • Navy Method: ±3-4% (very good for home use)
  • Calipers: ±5-7% (operator dependent)
  • Bioimpedance: ±8-10% (least reliable)

Why Body Fat % Matters More Than Weight

Two people at the same weight can look completely different based on body composition. Muscle is denser than fat, so a lean, muscular person may weigh more but look leaner than someone at lower weight with higher body fat.

Healthy Body Fat Ranges:

  • Men - Essential: 2-5% (athletes only)
  • Men - Athletic: 6-13% (fit, visible abs)
  • Men - Fitness: 14-17% (healthy, lean)
  • Women - Essential: 10-13% (athletes only)
  • Women - Athletic: 14-20% (fit, toned)
  • Women - Fitness: 21-24% (healthy, lean)

When to Use the Body Fat Calculator

Best times to measure body composition

Starting Body Recomposition

Before attempting to lose fat and build muscle, establish your baseline. Body fat % is the best metric for tracking recomp progress.

When Scale Doesn't Match Mirror

Weight going up but looking leaner? Or weight stable but clothes fit better? Body fat explains the disconnect between scale and appearance.

Monthly Progress Tracking

Measure monthly (same time, same conditions) to track true progress. Compare body fat % over time, not just scale weight.

Measurement Best Practices

For Accurate Results:

  • • Measure in morning, before eating or drinking
  • • Use same tape measure each time
  • • Measure over bare skin, not clothing
  • • Keep tape snug but not compressing
  • • Take 3 measurements, use average
  • • Measure same spots each time (mark with pen)

Common Measurement Errors:

  • • Measuring after eating or drinking water
  • • Different tape measure each time
  • • Pulling tape too tight or too loose
  • • Measuring different locations each time
  • • Not measuring at same time of day
  • • Testing more than once per month

Complete Your Health Assessment

BMI Calculator

Compare BMI with body fat for complete picture

Calculate BMI

Lean Body Mass

Calculate muscle mass and fat-free mass

Calculate LBM

TDEE Calculator

Calculate daily calorie needs for fat loss

Calculate TDEE