Estimate your body fat percentage using three different methods: US Navy, BMI-based, and skinfold. Compare results and find your fitness category.
Body fat percentage is the proportion of your total body weight that is fat, with the rest being muscle, bone, organs and water. It is a more useful measure of fitness than weight or BMI alone, because it separates fat from muscle. A healthy range is roughly 10–20% for men and 18–28% for women, varying with age and fitness level.
| Method | Body Fat % | Category |
|---|
There are several ways to estimate body fat, from free tape-measure methods to clinical scans. Each trades accuracy for cost and convenience.
| Method | Accuracy | Cost / Access |
|---|---|---|
| US Navy (tape measure) | Good estimate | Free — used by this calculator |
| Skinfold calipers | Good with practice | Low cost, needs technique |
| Bioelectrical impedance (BIA) | Moderate, varies with hydration | Smart scales, gyms |
| DEXA scan | Very high | Clinic, higher cost |
| Hydrostatic weighing | Very high | Specialist labs |
This calculator uses the US Navy circumference method — it estimates body fat from your height and a few tape measurements.
Two people can weigh exactly the same but look and perform very differently, because muscle is denser than fat. This is why the scale alone can be misleading.
| Feature | Body Fat | Muscle |
|---|---|---|
| Density | Lower — takes more space | Higher — more compact |
| Effect on metabolism | Burns few calories at rest | Burns more calories at rest |
| On the scale | Same weight, larger size | Same weight, leaner look |
| Health role | Some is essential; excess raises risk | Supports strength and metabolism |
This is also why body fat percentage often tells you more than weight or BMI: it separates fat from the muscle, bone and water that make up the rest of your body.
| Category | Men | Women |
|---|---|---|
| Essential fat | 2–5% | 10–13% |
| Athletes | 6–13% | 14–20% |
| Fitness | 14–17% | 21–24% |
| Average (acceptable) | 18–24% | 25–31% |
| Obese | 25%+ | 32%+ |
US Navy Method: Uses height, neck, and waist (and hip for women) circumference measurements. Accurate to within 3–4% of DEXA scan results for most people.
BMI Method: Uses the Deurenberg formula, which estimates body fat from BMI, age, and sex. Less accurate than the Navy method for athletes and muscular individuals.
The AIHW considers waist circumference a key indicator of abdominal obesity risk. Thresholds: men ≥94 cm (increased risk), ≥102 cm (substantially increased risk); women ≥80 cm (increased risk), ≥88 cm (substantially increased risk).
Dual-energy X-ray absorptiometry (DEXA) provides the most accurate body composition measurement. DEXA scans are widely available in Australia at radiology clinics and sports medicine facilities, often without a referral, typically costing $60–$200.
Body fat percentage is the proportion of your total body weight that is fat tissue, expressed as a percentage. Unlike weight alone, body fat % distinguishes between fat mass and lean mass (muscle, bone, organs, water). Two people with identical weight and height can have vastly different body compositions — and very different health risk profiles.
| Category | Men | Women |
|---|---|---|
| Essential fat (minimum for survival) | 3–5% | 10–13% |
| Athletic | 6–13% | 14–20% |
| Fitness | 14–17% | 21–24% |
| Acceptable (average) | 18–24% | 25–31% |
| Obese | 25%+ | 32%+ |
These ranges are from the American Council on Exercise (ACE) and are widely referenced in fitness contexts. The AIHW uses slightly different clinical thresholds for disease risk assessment in the Australian population.
Measurement tips: measure waist at the narrowest point (between ribs and hips); neck just below the larynx; hips at the widest point. All measurements in centimetres. Average 2-3 measurements for accuracy.
| Measure | Considers Muscle? | Considers Fat Distribution? | Equipment Needed |
|---|---|---|---|
| BMI | No | No | Scale + height measure |
| Body fat % (circumference) | Partially | Partially | Tape measure |
| Waist circumference | No | Yes (abdominal) | Tape measure |
| DEXA scan | Yes | Yes | Radiology clinic ($60-$200) |
What is a healthy body fat percentage?
For men: 14-17% is fitness range; 18-24% is acceptable. For women: 21-24% is fitness; 25-31% is acceptable. Athletes may be 6-13% (men) or 14-20% (women). Below essential fat levels (3-5% men, 10-13% women) carries serious health risks. Above 25% (men) or 32% (women) is classified as obese.
How accurate is the Navy body fat calculator?
The Navy circumference method has an accuracy of approximately ±3-4% compared to DEXA (gold standard). It consistently overestimates body fat in very lean individuals and underestimates in very obese individuals. For most people in the normal to overweight range, it provides a useful tracking tool even if the absolute number is imperfect.
What is the most accurate way to measure body fat in Australia?
DEXA (dual-energy X-ray absorptiometry) is the gold standard, available at radiology clinics for approximately $60-$200. Hydrostatic (underwater) weighing is equally accurate but less accessible. Air displacement plethysmography (Bod Pod) is accurate but rare. For home tracking, consistent Navy method or skinfold measurements track trends well even if absolute values are imperfect.
Can I have a healthy BMI but high body fat?
Yes. This is called 'normal weight obesity' or 'skinny fat.' A person with low muscle mass and high fat can have a normal BMI (18.5-24.9) while carrying unhealthy body fat levels — typically 25%+ for men or 32%+ for women. Conversely, muscular athletes often have BMI above 25 (overweight) while carrying very little body fat.
How do I calculate my body fat percentage?
The easiest free method is the US Navy formula, which uses your height plus waist and neck measurements (and hips for women). Enter these in the calculator above and it estimates your body fat percentage. For higher accuracy, a DEXA scan or skinfold test by a professional is better.
What is a healthy body fat percentage for men and women?
For men, roughly 10–20% is healthy, with 6–13% typical for athletes. For women, roughly 18–28% is healthy, with 14–20% for athletes. Women naturally carry more essential fat than men. Healthy ranges also increase gradually with age.
Is body fat percentage better than BMI?
Often, yes. BMI only compares weight to height and cannot tell muscle from fat, so it can misjudge muscular or older people. Body fat percentage directly measures the fat you carry, giving a clearer picture of body composition and health risk.
What is the difference between visceral and subcutaneous fat?
Subcutaneous fat sits just under the skin and is the fat you can pinch. Visceral fat is stored deeper, around your organs, and carries higher health risks even at a normal weight. A large waist measurement is a warning sign of excess visceral fat.
How accurate are body fat calculators?
Tape-measure methods like the US Navy formula give a reasonable estimate, usually within a few percent, but they are not as precise as a DEXA scan. Hydration, measurement technique and body shape all affect the result, so track the trend over time rather than fixating on one number.
Does body fat percentage change with age?
Yes. Body fat percentage tends to rise with age as muscle mass naturally declines, even if your weight stays the same. This is why healthy body fat ranges are set a little higher for older adults, and why maintaining muscle through activity matters.
How often should I measure my body fat?
Every two to four weeks is enough to see a real trend without being misled by daily fluctuations. Always measure under the same conditions — same time of day, same hydration, same method — so your readings are comparable.