Body Fat Percentage Calculator
Calculate your body fat percentage using the US Navy circumference method or YMCA formula. See your fat mass, lean mass, and body composition category based on ACE guidelines.
e.g. 185 lbs
e.g. 5 ft 10 in
Narrowest point, e.g. 34 in
Below larynx, e.g. 16 in
Your Body Fat %
An athletic body fat percentage indicating a high degree of fitness with visible muscle definition. Typical of competitive athletes, bodybuilders, and highly active individuals.
Fat Mass
16.8 lbs
Lean Mass
168.2 lbs
How to Use This Body Fat Calculator
This calculator estimates body fat percentage from simple tape measurements. Follow these steps:
- Select your sex and unit system — the formula and category thresholds differ for men and women. Choose Imperial (inches, pounds) or Metric (centimetres, kilograms).
- Enter your measurements — weight, height, waist circumference, and neck circumference. Women also enter hip circumference. Use a flexible tape measure and measure in the morning for consistency.
- Choose your method — the Navy method uses height for more accuracy; the YMCA method uses weight instead and requires only waist measurement. Navy is generally recommended.
- Read your results — see your body fat percentage, ACE category, fat mass, lean mass, and a visual scale showing where you fall compared to the five fitness categories.
Results update in real time as you type. You can share or print your results using the buttons above the result card.
Body Fat Formulas & Categories
US Navy Method
Uses height and circumference measurements. All values must be in inches. If using metric, divide centimetres by 2.54.
Men
BF% = 495 ÷ (1.0324 − 0.19077 × log₁₀(waist − neck) + 0.15456 × log₁₀(height)) − 450Women
BF% = 495 ÷ (1.29579 − 0.35004 × log₁₀(waist + hip − neck) + 0.22100 × log₁₀(height)) − 450YMCA Method
Uses waist circumference and bodyweight only. Waist in inches, weight in lbs.
Men
BF% = (−98.42 + 4.15 × waist − 0.082 × weight) ÷ weight × 100Women
BF% = (−76.76 + 4.15 × waist − 0.082 × weight) ÷ weight × 100ACE Body Fat Categories
| Category | Men | Women |
|---|---|---|
| Essential Fat | 2–5% | 10–13% |
| Athletes | 6–13% | 14–20% |
| Fitness | 14–17% | 21–24% |
| Acceptable | 18–24% | 25–31% |
| Obese | 25%+ | 32%+ |
Frequently Asked Questions
Body fat percentage is the proportion of your total body weight that is fat tissue. Unlike BMI, it directly measures body composition. It includes essential fat (needed for normal body function) and storage fat. A lower body fat percentage generally indicates better fitness, though some essential fat is required for health.
According to the American Council on Exercise (ACE): Men — Essential Fat: 2–5% | Athletes: 6–13% | Fitness: 14–17% | Acceptable: 18–24% | Obese: 25%+. Women — Essential Fat: 10–13% | Athletes: 14–20% | Fitness: 21–24% | Acceptable: 25–31% | Obese: 32%+. Women naturally carry more essential fat due to hormonal and reproductive functions.
The US Navy circumference method is generally accurate to within 3–4 percentage points for most people. It is more accurate than BMI for estimating body composition since it accounts for body shape via circumference measurements. For the most accurate results, use a DEXA scan (dual-energy X-ray absorptiometry), which is considered the gold standard.
For the Navy method, measure your waist at the narrowest point (for men) or at the navel level (for women). Keep the tape parallel to the floor, relaxed (not sucked in). For women, also measure the widest point of the hips. Measure the neck just below the larynx (Adam's apple). Take measurements in the morning for consistency.
BMI (Body Mass Index) uses only height and weight and cannot distinguish between fat and muscle. A muscular athlete may have a high BMI but low body fat. Body fat percentage directly measures fat mass. You can have a "normal" BMI but high body fat (called "normal weight obesity") or a high BMI with low body fat (as in athletes). Body fat is the more accurate measure of body composition.
To reduce body fat: (1) Create a moderate calorie deficit (300–500 calories/day); (2) Prioritize protein (0.7–1g per lb bodyweight) to preserve muscle; (3) Incorporate strength training to maintain/build lean mass; (4) Include cardio for additional calorie burn. Losing 0.5–1% body fat per month is a sustainable, realistic goal.
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