Methods 1: Calculate the percentage of body fat at home.
1, determine your body mass index (BMI). Body mass index is calculated according to your weight and height. The easiest way to calculate body mass index is to use an online calculator. You can simply enter the words "calculate body mass index" in your favorite search engine. You will be asked to enter your weight and height in the calculator. If you like to do your own calculations, you can! If you use the metric system, the formula is weight (kg) divided by the square of height. For example, your height is 175cm (1.75m), your weight is 78kg, and your body mass index is 25.5.
2. Use your body mass index to find your body fat percentage. The equation is (1.20xBMI)+(0.23x age) -( 10.8x sex) -5.4. If you are a man, your gender number is 1. If you are a woman, your gender number is 0. For example, if your body mass index is 25.5 and you are a 30-year-old male, your formula is (1.2x25.5)+(.23x30)-(10.8x1)-5.4. This will be equal to 30.6+6.9- 18.
3. Measure your bioelectrical impedance. Adipose tissue cannot conduct electricity. When you measure your bioelectrical impedance, you are testing the content of adipose tissue relative to other tissues in your body. This method does not require professionals and the equipment is not very expensive. You must stand barefoot on a metal plate, which will send current to your whole body. When the equipment works normally and the tested person always follows certain laws, the obtained bioelectrical impedance has an error of only 3%. Instruments that can measure bioelectrical impedance can be used at home, and can also be bought online or in fitness shops. This method requires fasting and water prohibition 4 hours in advance, no exercise for 12 hours, no drinking for 48 hours, no diuretics, and complete urine.
This method can be used in health clubs, health fairs and schools, and is usually free or at a low cost.
4. Measure yourself with a tape measure. This is not the most accurate method, but it can give you an estimate of body fat percentage. The most traditional method to calculate the percentage of fat with a tape measure is the method of the US Navy. Please refer to "How to Measure Body Fat by the U.S. Navy Method".
5. Check your body fat percentage with calipers. This method requires extracting your fat from muscle tissue and squeezing them with calipers. Then measure and compare according to the chart provided. If the test is applied correctly, the test has an error of 3%. For people who are very thin or fat, the measurement error is large. This test is suitable for schools, health clubs, entertainment projects, hospitals and laboratories. It's cheap and usually free.
Method 2: Calculate the percentage of body fat with an instrument.
1, underwater weighing machine. Underwater weighing is the most accurate method to determine the percentage of body fat, which can calculate how much water the body produces. If the test is carried out according to the guiding principles, the error is 1.5%. To find this facility near you, you can use your favorite search engine to search for "underwater weighing machine near [your city]". You know, the subject must be able to expel all the air from the lungs. This only applies to research institutions and specialized facilities. If you don't take part in a study in the factory, it will be very expensive to do.
2. Measure with infrared analyzer (IRI). This method uses an optical fiber probe (or light absorption tool) to measure the composition (fat and moisture content) of various parts of your body to measure the body composition. It has an error of more than 4%, however, thinner and fatter people have greater errors. It may be available in some health clubs and slimming centers, and the cost is lower.
3. use BodPod facilities. BodPod measures body composition by air replacement. This method has an error of 3%. It is only suitable for a few research laboratories and professional sports facilities. This is a good way to measure the body composition of children, the elderly, the obese and the disabled.
4. Use equipment equipped with dual-energy X-ray bone densitometer (DEXA) scanner. DEXA is a very accurate method to determine body composition. It uses a combination of two X-rays to calculate body composition. It is only suitable for scientific research facilities, but it is usually available for free use by people who participate in research.