Body Fat Calculator

Measure your body fat percentage using the proven US Navy formula. Enter your measurements to get your fat percentage and fitness category.

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Gender

Measure at the narrowest point for waist and at the widest point for hips. Keep the tape horizontal.

Body fat categories (ACE)

CategoryMale (%)Female (%)
Essential fat2 – 510 – 13
Athlete6 – 1314 – 20
Fitness14 – 1721 – 24
Average18 – 2425 – 31
Obese≥ 25≥ 32

US Navy formula

Male:
86.010 × log(bel−boyun) − 70.041 × log(boy) + 36.76
Female:
163.205 × log(bel+kalça−boyun) − 97.684 × log(boy) − 78.387

Developed by Hodgdon and Beckett (1984). Accuracy within 3-4% of DEXA scan results for most adults.

How to use?

  1. 1
    Select genderChoose male or female — the formula and reference ranges differ between sexes.
  2. 2
    Enter measurementsHeight in cm, waist and neck in cm. Women also need hip circumference. Weight is optional — used to calculate fat mass in kg.
  3. 3
    Read your resultThe calculator shows your body fat percentage, fitness category and fat mass. Compare with the ACE reference table below.

FAQ

What is a healthy body fat percentage?
For men, 6–17% is the athlete/fitness range; 18–24% is average; 25%+ is obese. For women, 14–24% is athlete/fitness; 25–31% is average; 32%+ is obese. Essential fat (needed for survival) is 2–5% for men and 10–13% for women.
How accurate is the Navy method?
The US Navy circumference method is accurate within 3–4 percentage points for most adults compared to DEXA (gold standard). It is less accurate for very muscular or very obese individuals. For best results, measure in the morning before eating.
Where should I measure waist circumference?
Men: measure at the navel level. Women: measure at the narrowest point of the torso (usually just above the navel). Keep the tape parallel to the floor and measure after a normal exhale.

Body Fat Percentage: What It Means and Why It Matters

Body fat percentage is the proportion of your total body weight that is fat tissue. Unlike BMI, which only considers height and weight, body fat percentage distinguishes between fat mass and lean mass (muscle, bone, water, organs). Two people with the same BMI can have very different body compositions and health risks.

The US Navy Method Explained

The US Navy circumference method was developed by Hodgdon and Beckett in 1984 for military fitness testing. It uses simple tape measurements — waist, neck, and (for women) hips — combined with height to estimate body fat. Studies show it agrees with DEXA scan results within 3–4 percentage points for most adults. It is one of the most practical field methods because it requires only a measuring tape.

How to Take Accurate Measurements

Measure in the morning, before eating. Stand upright and relaxed. For waist: measure at the navel (men) or narrowest point (women). For neck: measure below the larynx, sloping slightly downward. For hips (women): measure at the widest point. Take each measurement twice and use the average.

Reducing Body Fat Safely

A calorie deficit of 300–500 kcal per day combined with resistance training is the evidence-based approach to losing fat while preserving muscle. Crash diets reduce both fat and muscle, worsening your body composition. Track progress every 4 weeks — daily fluctuations in hydration mask real changes.

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