OmniTools

Body Fat Percentage Calculator

Estimate body fat percentage using US Navy circumference measurements.

Basis: The U.S. Navy (Hodgdon–Beckett) circumference method — adopted by the US Department of Defense and widely used internationally·2026-08-28 verified·Not reviewed by a medical professional·Editorial policy

Before you rely on this

Tape-measure estimation carries a standard error of about ±3–4 percentage points. Results differ from DEXA, hydrostatic weighing and bioelectrical impedance, and comparing figures taken by different methods can show change where there is none.

Tool Overview & Key Purpose

Calculate body fat percentage, lean body mass, and total fat mass using the U.S. Navy tape measure formula.

Step-by-Step Usage Instructions

1STEP 1

Select gender and enter height and weight.

2STEP 2

Measure neck and waist circumference (plus hip circumference for women).

3STEP 3

View estimated body fat percentage (%), fat mass, and lean body mass.

4STEP 4

Compare results against athletic, fit, average, or obese reference ranges.

Real-World Scenarios & Practical Cases

3 Practical CasesScenario #1

Home Fitness Body Fat Tracking

A 175 lb male with 32-inch waist and 15-inch neck measures ~14.2% body fat (athletic lean condition).

Requires only a standard tape measure without expensive scales.Scenario #2

Monitoring Muscle Loss During Cuts

Track lean mass versus fat mass changes to verify weight lost comes from fat, not muscle tissue.

Preserving lean mass keeps metabolism high.Scenario #3

Abdominal Fat Health Assessment

Monitor waist circumference changes to evaluate visceral fat reduction and metabolic health risks.

Waist size directly correlates with visceral fat.Circumference-based body fat formulaUS Navy Method based on neck, waist, hip circumferences and height logarithm formula.

Pro Tips & Key Considerations

Take circumference measurements relaxed at the end of a normal exhale.Measure consistently in the morning on an empty stomach for accurate tracking.

Frequently Asked Questions (FAQ)

Sources & References

PubMed — "History of the U.S. Navy Body Composition Program"ACE Fitness — Guidelines for Percentage of Body Fat

Basis: The U.S. Navy (Hodgdon–Beckett) circumference method — adopted by the US Department of Defense and widely used internationally · 2026-08-28 verified