Body Fat Calculator

Calculate body fat percentage using the U.S. Navy method with waist, neck, and height measurements.

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Body Fat Percentage
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Category —
Fat Mass —
Lean Mass —
Extended More scenarios, charts & detailed breakdown ▾
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Body Fat %
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Category —
Fat Mass —
Lean Mass —
Professional Full parameters & maximum detail ▾
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Body Fat by Method

Navy Method BF% —
Jackson-Pollock 3-Site BF% —
Deurenberg (BMI-based) BF% —
Average BF% —

Body Composition

Category —
Fat Mass —
Lean Mass —

Goals

Ideal Body Fat Range —
Fat to Lose for Ideal Range —

How to Use This Calculator

Enter your gender, waist circumference, neck circumference, and height. Women should also enter hip measurement under "More options." For best results, measure in the morning before eating.

Formula

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

Example

Example: A male with 34" waist, 15" neck, 70" height: BF% = 495 / (1.0324 - 0.19077 × log10(48.26) + 0.15456 × log10(177.8)) - 450 ≈ 17.7% (Average/Fitness range).

Frequently Asked Questions

  • The Navy method is accurate within 1-3% for most people. It is less accurate for very lean or very overweight individuals. DEXA scans are the gold standard.
  • For men: 14-17% is fitness level, 18-24% is average. For women: 21-24% is fitness, 25-31% is average. Athletes may be lower.
  • Measure at the navel (belly button) level for men. For women, measure at the narrowest point of the waist.
  • The Navy formula uses different equations for men and women. The female formula requires waist, hip, neck, and height for accuracy.

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Sources & References (5) ▾
  1. Hodgdon JA & Beckett MB — Prediction of percent body fat for U.S. Navy men from body circumferences and height. Report No. 84-11 (1984). Naval Health Research Center — U.S. Navy / NHRC
  2. Deurenberg P et al. — Body mass index as a measure of body fatness: age and sex-specific prediction formulas. Br J Nutr. 1991;65(2):105-114 — British Journal of Nutrition
  3. American College of Sports Medicine — ACSM's Guidelines for Exercise Testing and Prescription, 11th ed. (2022) — ACSM
  4. NIH/NHLBI — Body Fat Measurement and Assessment — NIH / NHLBI
  5. Gallagher D et al. — Healthy percentage body fat ranges: an approach for developing guidelines based on body mass index. Am J Clin Nutr. 2000;72(3):694-701 — American Journal of Clinical Nutrition