Body Fat Calculator

One of the best methods of estimating the fat content of a person's body was developed by US Navy and it calculates body fat with good precision. This parameter is determined for all service members of the US Navy since they are required to meet certain percent body fat (%BF) standards as a condition of military service. Read on to understand the equation and to check if you could join the naval forces.

What are the required measurements?

You'll only need a measuring tape. Then, start taking measurements:
  1. Height - make sure you stand up straight and barefoot.
  2. Neck - the circumference should be measured just underneath the larynx (Adam's apple).
  3. Waist - should be measured horizontally, around the narrowest part of the abdomen for women and at the at the navel level for men.
  4. Hips - should be measured at the widest part of the buttocks or hip. You can input the values in both imperial and metric units.
If you have already taken these measurements, you can also calculate your body shape, waist to hip ratio and waist to height ratio.

What formula does the US Navy body fat calculator use?

The equation was developed at the Naval Health Research Center (NHRC), San Diego, California. For men, it looks like this:

%BF = 495 / ( 1.0324 - 0.19077 * log10( waist - neck ) + 0.15456 * log10( height ) ) - 450

And for women:

%BF = 495 / ( 1.29579 - 0.35004 * log10( waist + hip - neck ) + 0.22100 * log10( height ) ) - 45

Please note that the formulas presented above are for measurements in metric units.

The US Navy body fat standards

The limit of body fat percentage for US Navy service members:
  • Age 18 to 21 - 22% for males, 33% for females;
  • Age 22 to 29 - 23% for males, 34% for females;
  • Age 30 to 39 - 24% for males, 35% for females;
  • Age over 40 - 26% for males, 36% for females.
Body fat percentage plays an important role in distinguishing between a healthy and an obese individual, as it has a greater ability to differentiate between lean mass and fat mass compared to BMI.