Percent body fat (BFP) per person or other living thing is the total fat mass divided by the total body mass multiplied by 100; Body fat includes essential body fat and stored body fat. It is essential for maintaining vital and reproductive functions.
The three most popular methods are bioelectrical impedance, bending, and underwater weighing. You can buy a body fat percentage machine online also.
Bioelectric impedance: measurement uses a machine that passes an electric current through your body that measures the total water in your body and the lean muscle tissue of your body. This is a very popular method of measuring body fat and is easy to perform, painless and non-invasive.
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Skinfold calipers: measure skinfold thickness, which measures the amount of fat under your skin. This type of body fat meter requires a skilled and experienced technician or you may get very inaccurate results.
Underwater weighing: is the most invasive technique for measuring body fat. This may require a special water tank and some advanced gauges. To get a reading with this system, you have to sit in a large tank or tub of water on a special seat. Many people say that this method is the most accurate way to measure body fat. But because it is the most invasive and requires special equipment, it is not the most commonly used method.