How does the U.S. Navy method work?

The U.S. Navy method estimates body fat using circumference measurements of the waist, neck, and hip (for women), along with height. It uses a logarithmic formula developed by the U.S. Navy for fitness assessments.

What is a healthy body fat percentage?

For men, 10–20% body fat is considered healthy. For women, 18–28% is considered healthy. Athletes may have lower percentages, while essential fat is about 2–5% for men and 10–13% for women.

Body Fat Calculator — Free Online Body Fat Percentage Calculator

Your Measurements

Your Results

Body Fat 18.5 % Fitness

Essential Athlete Fitness Average Obese

Body Fat Percentage 18.5%

Fat Mass 13.0 kg

Lean Mass 57.1 kg

Category Fitness

Body Fat Categories Male

Category	Body Fat Range
Essential Fat	2 – 5%
Athlete	6 – 13%
Fitness	14 – 17%
Average	18 – 24%
Obese	≥ 25%

What is Body Fat Percentage?

Body fat percentage is the proportion of your total body weight that consists of fat tissue. Unlike BMI, which only uses height and weight, body fat percentage provides a more accurate picture of your body composition by distinguishing between fat mass and lean mass (muscle, bone, water, organs).

U.S. Navy Method Formula

Men:

BF% = 86.010 × log₁₀(waist − neck) − 70.041 × log₁₀(height) + 36.76

Women:

BF% = 163.205 × log₁₀(waist + hip − neck) − 97.684 × log₁₀(height) − 78.387

All measurements in centimetres.

Body Fat Categories

Essential Fat: 2–5% (men) / 10–13% (women) — Minimum fat needed for basic physiological function.
Athlete: 6–13% (men) / 14–20% (women) — Typical of competitive athletes.
Fitness: 14–17% (men) / 21–24% (women) — Fit and active individuals.
Average: 18–24% (men) / 25–31% (women) — Acceptable range for general health.
Obese: ≥25% (men) / ≥32% (women) — Elevated health risk from excess body fat.

How to Measure

Height: Stand straight against a wall without shoes.
Waist: Measure around your waist at the navel level, keeping the tape horizontal.
Neck: Measure just below the larynx (Adam’s apple), tape sloping slightly downward at the front.
Hip (women): Measure at the widest point of your hips / buttocks.

Use a flexible measuring tape and measure against bare skin for the most accurate results. Take each measurement twice and use the average.

Limitations

The Navy method is an estimation — DEXA scans and hydrostatic weighing are more accurate.
Results may be less accurate for very muscular or very lean individuals.
Water retention, bloating, and posture can affect circumference measurements.
The formula was developed primarily for military fitness assessment and may not apply equally to all populations.

Reducing Body Fat

Calorie Deficit: Consume fewer calories than you burn. A moderate deficit of 300–500 cal/day promotes fat loss while preserving muscle.
Strength Training: Resistance exercise builds lean mass, which increases your resting metabolism.
Protein Intake: Aim for 1.6–2.2 g per kg of body weight to support muscle retention during fat loss.
Cardio: Moderate cardio (150+ min/week) improves cardiovascular health and aids fat loss.
Sleep & Recovery: 7–9 hours of quality sleep supports hormonal balance and recovery.

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