How to Calculate Body Fat Content

The amount of body fat one should have differs depending on age and gender. The ideal for women younger than 40 is between 21 and 33 percent, while women older than 40 should have 2 to 3 percent more. The ideal for men younger than 40 is between 8 and 19 percent, and men older than 40 should have 3 to 6 percent more. The four most accurate methods for calculating body fat are presented below in order from the least to the most accurate.

Things You'll Need

• Scale
• Tape measure
• Notebook
• Bioelectric impedance scale

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Instructions

• 1

  Weigh yourself, then measure your waist circumference at your navel. Women will also need to measure a wrist, a forearm and their hips--all measured at the widest point. Record the figures in pounds and inches. Use these numbers with the body fat calculator found in the Resources section below. This method is not very accurate for athletes or people who are excessively obese.

• 2

  Consult a trainer or nutritionist who has experience using body fat calipers. She will measure folds of skin in different parts of your body to provide you with a figure more accurate than the one obtained by the formula in Step 1. Results can vary if different people take the measurements, so have the same person take the readings each time.

• 3

  Use a bioelectric impedance scale. This scale will pass a small electric current through your body to measure body fat. Be sure to follow the manufacturer's directions closely. Results will vary according to the amount of water in your body.

• 4

  Find a gym or nearby university which has an underwater weighing tank. This is the most accurate method of calculating body fat, but it is not always easy to find a facility which offers this service.