What body fat percentage is considered healthy?

For men: essential fat is 2-5%, athletes 6-13%, fitness 14-17%, acceptable 18-24%, obese 25%+. For women: essential fat 10-13%, athletes 14-20%, fitness 21-24%, acceptable 25-31%, obese 32%+.

How accurate is the Navy body fat method?

The Navy method is accurate to within 1-3% for most people when measurements are taken correctly. It is less accurate for very muscular or very lean individuals. DEXA scans provide the gold standard at 1% accuracy.

Can I have too little body fat?

Yes. Essential body fat (2-5% for men, 10-13% for women) is necessary for organ function, hormone production, and insulation. Dropping below essential levels causes hormonal disruption, immune suppression, and organ damage.

Where does the body store fat?

Men tend to store fat abdominally (visceral and subcutaneous), while women store more in hips, thighs, and breasts. Visceral fat (around organs) is more metabolically dangerous than subcutaneous fat (under the skin).

How fast can I lose body fat?

A safe rate is 0.5-1% body fat per month, or 1-2 lbs of fat per week. Faster loss typically means you are also losing muscle. Maintain a moderate caloric deficit and prioritize strength training to preserve lean mass.

Body Fat Calculator

Estimate your body fat percentage using the US Navy circumference method — fast, free, and no gym equipment required.

Body Fat Calculator

Estimate your body fat percentage (US Navy Method)

Body Fat Calculator

US Navy method estimation

Waist (inches)

Neck (inches)

Height (inches)

Formula

BF% = 86.010 x log10(waist - neck) - 70.041 x log10(height) + 36.76 (male)

What Is Body Fat Percentage?

Body fat percentage is the proportion of your total body weight that comes from fat tissue. Unlike weight alone, it tells you how much of you is actually fat versus muscle, bone, and organs. For most people this number is far more meaningful than stepping on a scale — two people of identical weight can have vastly different health profiles depending on their body composition.

Fat falls into two broad categories: essential fat and storage fat. Essential fat (roughly 2–5% for men, 10–13% for women) is the minimum needed for organ protection, hormone regulation, and basic physiological function. Storage fat is the reserve energy deposited under the skin and around organs. Healthy ranges for men sit between 14–24%; for women, 21–31% — though athletic individuals typically fall well below these thresholds.

How to Use This Calculator

1Select your gender and enter your height in centimeters (or switch to inches).
2Measure and enter your waist circumference at the navel, and your neck circumference just below the larynx. Women also enter hip circumference at the widest point.
3Click Calculate to run the US Navy formula instantly.
4Review your body fat percentage and the category it falls into — Essential, Athletic, Fit, Acceptable, or Obese.

Formula & Healthy Ranges

US Navy Method:
  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 cm; height in cm

Healthy ranges:
  Men:   Essential 2–5% | Athletic 6–13% | Fit 14–17% | Acceptable 18–24% | Obese 25%+
  Women: Essential 10–13% | Athletic 14–20% | Fit 21–24% | Acceptable 25–31% | Obese 32%+

The US Navy method uses circumference measurements and is considered a reliable field estimate with roughly ±3–4% accuracy. For clinical precision, a DEXA scan remains the gold standard — but that requires medical equipment and a specialist.

Worked Examples

Example 1 — Man: Height 180 cm, Waist 85 cm, Neck 38 cm

BF% = 86.010 × log10(85 − 38) − 70.041 × log10(180) + 36.76 = 86.010 × log10(47) − 70.041 × log10(180) + 36.76 ≈ 86.010 × 1.6721 − 70.041 × 2.2553 + 36.76 ≈ 143.82 − 157.94 + 36.76 ≈ 16.8% — Fit range.

Example 2 — Woman: Height 165 cm, Waist 72 cm, Hip 95 cm, Neck 33 cm

BF% = 163.205 × log10(72 + 95 − 33) − 97.684 × log10(165) − 78.387 = 163.205 × log10(134) − 97.684 × log10(165) − 78.387 ≈ 163.205 × 2.1271 − 97.684 × 2.2175 − 78.387 ≈ 347.18 − 216.65 − 78.387 ≈ 24.3% — Fit range.

Example 3 — Man: Height 175 cm, Waist 100 cm, Neck 40 cm

BF% = 86.010 × log10(100 − 40) − 70.041 × log10(175) + 36.76 = 86.010 × log10(60) − 70.041 × log10(175) + 36.76 ≈ 86.010 × 1.7782 − 70.041 × 2.2430 + 36.76 ≈ 152.94 − 157.13 + 36.76 ≈ 26.1% — Obese range.

Frequently Asked Questions

Is body fat percentage more important than BMI?▾

For most practical purposes, yes. BMI only compares weight to height and cannot distinguish fat from muscle — a muscular athlete and a sedentary person of the same height and weight will have the same BMI but wildly different health profiles. Body fat percentage directly measures the fat-to-lean ratio, making it a far better indicator of metabolic health and fitness level.

How can I reduce body fat without losing muscle?▾

The key is a moderate calorie deficit (300–500 kcal/day below maintenance), high protein intake (1.6–2.2 g per kg of body weight), and consistent resistance training at least 3 days per week. This combination signals your body to preserve lean muscle while burning stored fat. Crash diets and extreme cardio tend to burn both fat and muscle indiscriminately.

What is visceral fat and why does it matter?▾

Visceral fat is the fat stored around your internal organs — liver, pancreas, intestines — rather than under the skin (subcutaneous fat). It is metabolically active and releases inflammatory compounds linked to insulin resistance, type 2 diabetes, cardiovascular disease, and certain cancers. A large waist circumference (over 94 cm for men, 80 cm for women) is a commonly used proxy for elevated visceral fat.

Can I measure body fat accurately at home?▾

Home methods — including the US Navy formula used here — provide useful estimates but are not clinical measurements. Navy method accuracy is roughly ±3–4 percentage points. Bioelectrical impedance scales (common consumer devices) vary widely in accuracy, especially with hydration changes. DEXA scans and hydrostatic weighing are the most accurate options but require specialist facilities. For tracking trends over time, a consistent method like this calculator works well.

How does age affect body fat percentage?▾

As we age, metabolic rate slows, muscle mass naturally declines (sarcopenia), and hormonal changes encourage fat storage — particularly around the abdomen. A 50-year-old can have the same body fat percentage as a 25-year-old but a very different distribution of that fat. Many health guidelines adjust acceptable body fat ranges slightly upward for older adults to reflect these physiological changes while still flagging excess adiposity.