Health
Body Fat Calculator
Calculate your estimated body fat percentage using the US Navy tape-measure method.
Inputs
Results
Body Fat Percentage
0.0%
Lean Body Mass
0.0 kg
Fat Body Mass
0.0 kg
Fitness Category
Average
How It Works
The US Navy body fat calculator uses circumference tape-measure inputs (neck, waist, and hips for women) combined with height. The Navy formula uses logarithmic ratios to determine density, which maps directly to body fat percentages.\n\nWhile DEXA scans or hydrostatic weighing are gold standards, studies show that tape-measure circumferences track closely (within 3% accuracy) for general health screenings when taken at standard anatomical points.
Formula Used
Body Fat (Men) = 86.010 × log10(Waist − Neck) − 70.041 × log10(Height) + 36.76
This is the US Navy body density formula for men using imperial measurements. It uses logarithmic ratios of body circumferences to estimate fat tissue distribution relative to skeletal frame height.
Body Fat (Women) = 163.205 × log10(Waist + Hip − Neck) − 97.684 × log10(Height) − 78.387
This is the US Navy body density formula for women. It includes hip measurements to account for gynoid fat distribution patterns typical of female physiology.
Worked Example
Here is a step-by-step example of how these values are calculated:
Gender
Male
Height
180 cm
Neck
38 cm
Waist
88 cm
Result: Body Fat Percentage: 15.6%. Fitness Category: Fit.
Frequently Asked Questions
Where should circumferences be measured?
Neck: Just below the larynx, slanting slightly downward. Waist: Horizontally at the level of the navel for men, and at the narrowest point of the torso for women. Hips: Horizontally at the widest point of the gluteal muscles (females only).
Why does the female formula include hips?
Women have a biological predisposition to store adipose tissue in the gluteofemoral (hip and thigh) region, whereas men accumulate fat primarily in the abdominal region. The hips input corrects for these sex-specific fat distribution patterns.