Navy Method Calculator

Know Your Body Fat
Percentage

The same method used by the US Navy โ€” accurate, science-backed body fat estimation using only a tape measure. No guesswork.

โš  Beta feature โ€” estimates only. This tool uses your camera and body landmark detection to estimate measurements. Results can deviate 3โ€“8% from actual body fat due to clothing, lighting, distance, and body position. For precise results, use the Manual Input tab with a tape measure. A paid precision mode is planned for future updates.
1

Stand 2โ€“3 metres from camera in good lighting

2

Wear fitted clothing โ€” loose clothes reduce accuracy

3

Stand straight, arms slightly out, full body visible

๐Ÿง

Click Start Camera and stand in full view

Ready
Estimated measurements
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Neck (cm)
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Waist (cm)
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Hip (cm)
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Height (cm)
These values are automatically filled into the calculator. You can adjust them manually in the Manual Input tab.

Help us improve

Want a more accurate camera-based body fat scan? Register your interest โ€” if enough people ask for it, we'll build a precision version.

โ™ฅ Support on Ko-fi
Units
cm
Measure below the larynx
cm
At the narrowest point
cm
At the widest point
cm

Please fill in all required fields with valid measurements.

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% body fat
Your category

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Where you fall on the spectrum

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Fat Mass (kg)
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Lean Mass (kg)
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Ideal Range

Assessment

Training Focus

Nutrition Approach

Next Steps

Recommended Tools & Supplements

How It Works

The US Navy circumference method โ€” trusted, validated, and tape-measure only

The Formula

Developed by the US Navy, this method uses circumference measurements at key body sites to estimate body fat percentage. For men: neck and waist. For women: neck, waist, and hips. Validated against hydrostatic weighing with ยฑ3% accuracy.

How to Measure

Neck: Below the larynx (Adam's apple), perpendicular to neck axis.
Waist (M): At the narrowest point, usually at the navel.
Waist (F): At the narrowest point.
Hips (F): At the widest point of the buttocks.

Accuracy

The Navy method is one of the most accessible validated methods. It is less accurate than DEXA scanning but far more convenient. For best results, measure in the morning before eating, relax the abdomen naturally (don't hold it in), and take 2-3 measurements to average.

Limitations

This calculator estimates body fat, not body composition quality. Muscle distribution, bone density, hydration, and ethnicity all affect real body fat. Use this as a directional guide rather than a medical measurement.

Category Men Women Description
Essential Fat 2โ€“5% 10โ€“13% Minimum fat for organ & hormonal function
Athlete 6โ€“13% 14โ€“20% Typical for competitive athletes
Fitness 14โ€“17% 21โ€“24% Above average โ€” lean and active
Average 18โ€“24% 25โ€“31% Typical for non-athletic adults
Obese 25%+ 32%+ Associated with elevated health risks