# Body Fat Percentage Calculator

## Calculating Body Fat Values

This calculator can estimate a person’s percentage body fat using methods approved by the US Army and US Navy. The calculator needs a total of seven inputs, including:

• Whether the user would like the measurements to be entered in US Imperial units or using the metric system
• The age of the person measuring their body fat percentage
• The sex of the person being measured
• The person’s height, as measured in feet / inches or centimeters
• The circumference of the person’s neck, as measured in inches or centimeters
• The circumference of the person’s waist, as measured in inches or centimeters
• The circumference of the person’s hips, as measured in inches or centimeters. This value is only used for females

The calculator then provides the user with four outputs, including:

• Body fat percentage based on the formula used by the US Army
• Whether or not the body fat percentage meets the fitness standards established by the US Army
• Body fat percentage based on the formula used by the US Navy
• Whether or not the body fat percentage meets the fitness standards established by the US Navy

### How to Take Body Measurements Used in Calculating Body Fat %

It’s important to use the proper technique when taking body circumference measurements to ensure the body fat results are as accurate as possible. The US Army provides the following recommendations:

• The measuring tape should be made of a non-stretchable material, preferably fiberglass. Cloth tapes will stretch, while steel tapes will not conform to the body. Most measuring tapes used for sewing are made of fiberglass since it will not tear or stretch easily.
• The tape should also be 1/4 to 1/2 inch wide (0.6 to 1.2 cm) wide and a minimum of five feet (150 cm) in length.
• The tape should be applied such that it contacts the skin but does not compress underlying soft tissue.
• The tape should remain in a horizontal plane when taking all measurements.
• Height measurements should be made in stocking feet (no shoes) with the head held horizontal. Measurements should be rounded to the nearest half inch or centimeter.
• Neck measurements are made just below the larynx (Adam’s apple). The person being measured should be looking straight ahead with relaxed shoulders (not hunched).
• Waist measurements for males should be made across the naval (belly button), arms should be at the sides and the measurement should be taken at the end of a normal, relaxed exhalation. Measurements should be rounded down to the nearest half inch or centimeter.
• Waist measurements for females are taken at the narrowest part of the abdomen, which is usually halfway between the naval and the end of the sternum (breastbone). Arms should be at the sides and the measurement should be taken at the end of a normal, relaxed exhalation. Measurements should be rounded down to the nearest half inch or centimeter.
• Hip measurements (females only) should be taken so that the tape passes over the greatest protrusion of the gluteal muscle (buttocks). Measurements should be rounded down to the nearest half inch or centimeter.

Understanding the Calculator’s Output

This calculator provides the user with two body fat percentages, one each using the US Army and Navy formulas. The calculator also indicates whether the person meets the fitness standard of each agency. This standard is a function of both sex and age. In other words, the standard varies by age and whether the person being measured is a male or female.