Estimate your body fat percentage with the US Navy tape method. Get your category plus fat and lean mass. Free, no signup, metric and imperial.
Standing, no shoes
Below the larynx
At the navel
Optional — for fat & lean mass
This calculator uses the US Navy circumference (tape) method, developed by the Naval Health Research Center. It estimates body fat percentage from a few body measurements rather than calipers or a lab scan. For men it uses height, neck, and waist; for women it adds the hip circumference, because fat distribution differs by sex. All measurements are converted to centimeters and run through the official log-based equations.
It is not as precise as a DEXA scan or hydrostatic weighing — expect it to land within roughly 3–4 percentage points — but it only needs a tape measure, and it is remarkably consistent. That consistency is the point: if you measure the same way each time, the trend it shows is reliable even when the absolute number is a few points off.
The category label uses the American Council on Exercise ranges. For context, women carry more essential fat than men for normal hormonal and reproductive function, which is why every band sits higher:
| Category | Men | Women |
|---|---|---|
| Essential fat | 2–5% | 10–13% |
| Athletes | 6–13% | 14–20% |
| Fitness | 14–17% | 21–24% |
| Average | 18–24% | 25–31% |
| Above average | 25%+ | 32%+ |
If you enter your weight, the tool splits it into fat mass and lean mass (everything else — muscle, bone, organs, water). Watching lean mass hold steady while fat mass drops is the real signal that a cut is working, and it is a much better gauge than the scale weight alone.
Body fat moves slowly, so checking it once a week is plenty. What actually shifts it is the boring daily stuff — showing up to train, hitting your protein, and getting your steps. HabitBox is a free, ad-free habit tracker that lives on your home screen: set those as daily habits, tap once to log a check-in, and let the streak do the motivating. No account, on-device only, on iOS and Android.
Note: this is an estimate for healthy adults and is not a medical diagnosis. Body composition needs and healthy ranges vary with age, ethnicity, and individual circumstances — talk to a clinician for personalized guidance.
The US Navy circumference (tape) method is typically within about 3–4 percentage points of a DEXA scan for most people, according to the Naval Health Research Center work it was derived from. It is far less precise than DEXA or hydrostatic weighing, but it needs only a tape measure and is very consistent for tracking change over time.
Use a flexible tape, keep it snug but not compressing the skin, and measure on bare skin after a normal exhale. For men, measure the waist at the navel; for women, at the narrowest point. Measure the neck just below the larynx (Adam's apple), and women also measure the hips at the widest point.
Using ACE ranges, fitness-level body fat is roughly 14–17% for men and 21–24% for women, while the 'athletes' band is about 6–13% (men) and 14–20% (women). Essential fat — the minimum needed for normal function — is around 2–5% for men and 10–13% for women.
The female equation adds a hip measurement because fat distribution differs by sex, and including the hip circumference improves the estimate for women. Men's body fat is estimated from waist and neck only, plus height in both versions.
No — body fat changes slowly, so weekly or every-two-weeks is plenty. Daily fluctuations are mostly water and food, not fat. What helps far more is consistently tracking the daily habits that move it: training sessions, protein intake, and steps. That is exactly the kind of streak HabitBox is built for.
Body fat changes slowly — what changes it is consistent training, protein, and steps. HabitBox lets you set those as daily habits, tap once to log a check-in, and watch your streak grow. Free, no account, on-device, iOS and Android.
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