Body Fat Calculator
Estimate your body fat percentage using the US Navy method with waist, neck, and hip measurements.
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How to use this calculator
Men: 495/(1.0324−0.19077×log10(waist−neck)+0.15456×log10(height))−450. Women: add hip measurement.
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Select your biological sex.
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Enter your height in cm.
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Measure your waist circumference at the navel and enter it.
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Measure your neck circumference at the narrowest point and enter it.
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Women: also measure your hip circumference at the widest point.
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The result estimates your body fat percentage and fitness category.
Frequently asked questions
How accurate is the Navy body fat method?
The US Navy method is generally within 3–4% of DEXA scan results for most people. It is less accurate for very lean individuals and those with unusual body proportions. For most purposes it is a reliable, equipment-free estimate.
What is a healthy body fat percentage?
For men: essential fat 2–5%, athletes 6–13%, fitness 14–17%, average 18–24%, obese 25%+. For women: essential fat 10–13%, athletes 14–20%, fitness 21–24%, average 25–31%, obese 32%+.
Where should I measure my waist?
Measure at the navel (belly button) for the US Navy method. Stand relaxed, exhale normally, then measure. Do not suck in your stomach.
What other methods exist for measuring body fat?
DEXA scan (most accurate, medical setting), hydrostatic weighing, air displacement plethysmography (Bod Pod), skinfold calipers, and bioelectrical impedance scales. Each has different accuracy, cost, and convenience tradeoffs.
Body fat percentage: what it means
How to use the body fat
Use this body fat to your body fat percentage using the us navy method with waist, neck, and hip measurements. Enter your values above and get your result in seconds. The tool is free, works on all devices, and keeps your data private — nothing is stored or shared.
How the body fat works
The body fat calculator uses standard formulas used in health tracking, fitness planning, and wellness management. Enter your inputs, and the tool calculates the result instantly in your browser. No server-side processing means your data stays on your device. Results update in real time as you change inputs.
Why body fat matters more than weight
Body weight alone does not distinguish between muscle and fat. Two people at the same weight can have very different body compositions — one may be muscular and lean at 15% body fat; the other may be carrying excess fat at 30%. Body fat percentage is a far better indicator of health and fitness.
Healthy body fat ranges by category
Men — Essential: 2–5% | Athletic: 6–13% | Fitness: 14–17% | Average: 18–24% | Obese: 25%+. Women — Essential: 10–13% | Athletic: 14–20% | Fitness: 21–24% | Average: 25–31% | Obese: 32%+. Women have higher essential fat due to hormonal and reproductive needs.
Reducing body fat
Body fat is reduced through a calorie deficit (eating less than TDEE) combined with resistance training to preserve muscle mass. Crash diets reduce both fat and muscle. A moderate deficit (300–500 kcal/day) with protein intake of 1.6–2.2g/kg bodyweight is the most effective approach.
Body fat: how it works
This free tool provides a quick, evidence-based estimate for wellness planning. It uses standard formulas accepted by health professionals worldwide. Enter your measurements for an instant result — always follow up with a qualified practitioner for personal guidance.
Who uses this tool?
Athletes, fitness enthusiasts, nurses, and anyone monitoring their health use it as a starting point for wellness decisions. Share the output with your doctor or dietitian for a professional interpretation.
Learn more from an authoritative source:
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Results are estimates for informational purposes only and do not constitute professional financial, medical, legal, or technical advice. Read full disclaimer →