What's a healthy body fat percentage?

Per the American Council on Exercise, the fitness range is 14–17% for men and 21–24% for women. Athletes typically run lower; average ranges (18–24% men, 25–31% women) are not necessarily unhealthy. Going below the essential range (under 5% for men, under 13% for women) is associated with hormonal and immune risks.

How do I measure neck, waist, and hip correctly?

Use a flexible (cloth or fiber) tape, snug but not compressing. Neck: just below the larynx (Adam's apple), looking straight ahead. Waist: at the navel for men; at the narrowest point of the torso for women. Hip (women only): at the widest point of the buttocks. Take each measurement twice and average if the readings differ by more than half an inch.

Why does this calculator ask for height?

Height is part of the formula — it normalizes the circumference measurements relative to body size. Without height, the formula would systematically over- or underestimate body fat in tall and short individuals.

Is body fat the same as visceral fat?

No. Total body fat includes subcutaneous fat (under the skin) and visceral fat (around internal organs). Visceral fat is the metabolically dangerous kind, but circumference-based methods can't separate the two. Waist circumference itself is a useful proxy: 102 cm (40 in) or more in men, 88 cm (35 in) or more in women, is associated with higher metabolic risk.

How does body fat compare with BMI?

BMI is a height-weight ratio with no composition data. Body fat percentage measures actual fat mass. A muscular person can have a high BMI and low body fat; a sedentary person can have a normal BMI and high body fat (sometimes called normal-weight obesity). When both are available, body fat percentage is more informative.

Body Fat Calculator — US Navy method

Body Fat Calculator

US Navy circumference method · ACE category classification

Implements a published clinical formula — see citation

Maintained by TheHealthTools team. Not medical advice.

Sex

Height (ft)

Inches

Neck (in)

Waist (in)

How to measure: use a flexible tape, snug but not compressing. Neck below the larynx. Waist at the navel for men, at the narrowest point for women. Hip (women only) at the widest point of the buttocks.

Why circumference works (and where it doesn't)

The US Navy method, developed by Hodgdon and Beckett in 1984, estimates body fat from a small number of tape measurements normalized by height. Compared with DEXA — the clinical gold standard — it's accurate to about ±3–4% on average for adult populations. That's far more precise than BMI for body composition, and it's the most accurate at-home option requiring nothing but a flexible tape.

Three caveats. First, the formula was developed in mostly healthy young-to-middle-aged adults; accuracy can be lower at extremes of age or body composition. Second, where you carry fat changes the result — abdominal fat is read more strongly than peripheral fat. Third, even small measurement inconsistencies (1 cm) move the result by a few percent, so measure twice and average.

Frequently asked questions

Compared with DEXA (the clinical gold standard), the US Navy circumference method is accurate to about ±3–4% on average for adult populations. Individual error can be larger, especially at extremes of body composition. It's far more accurate than BMI for estimating body fat and far more practical than DEXA for at-home use.