How the Body Fat Calculator works?
The Navy Body Fat Test, officially known as the Body Composition Assessment (BCA), is a method used by the United States Navy to assess the body fat percentage of its personnel. The purpose of the test is to ensure that members of the Navy maintain a level of physical fitness that meets the service’s standards.
How to calculate it?
The Navy Body Fat Test uses a specific formula to estimate body fat percentage based on the measurements of the neck, waist, and, for women, the hips. The formula is different for men and women. Here are the one used here:
- bodyFatPercentage = 495 / (1.0324 – 0.19077 * Math.log10(waist – neck) + 0.15456 * Math.log10(height)) – 450;
In these formulas:
- The measurements are taken in inches.
- The waist measurement is taken at the narrowest point, usually around the navel.
- The neck measurement is taken just below the larynx, with the tape sloping slightly downward to the front.
- For women, the hip measurement is taken at the widest point around the buttocks.
The logarithmic function in the formula is used to account for the fact that body fat distribution is not linear, meaning that as the circumference measurements increase, the body fat percentage may increase more than proportionally.
It’s important to note that while the Navy Body Fat Test provides a quick and relatively simple method for estimating body fat percentage, it has limitations and may not be as accurate as more sophisticated methods like Dual-Energy X-ray Absorptiometry (DEXA) scans or hydrostatic weighing. Additionally, factors such as age, fitness level, and individual body composition variations can affect the accuracy of the estimate.