How to Tell My Body Fat Percentage

Your body fat percentage measures the portion of your weight that consists of fats. Whenever you are beginning a training regiment with a personal trainer, he will typically perform a body fat percentage measurement to assess your level of fitness. With a tape measure and scale, you can measure your own body fat percentage so you can monitor your own progress, should you decide to decrease your fat percentage.

Things You'll Need

• Scale
• Tape measure

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Instructions

For Men

• 1

  Weigh yourself on a scale. Then wrap a tape measure around your middle --- at the point where your belt would go --- to find the circumference of your waist.

• 2

  Calculate your lean body mass using this formula: (weight x 1.082) - (waist x 4.15) + 94.42. For example, if you weight 200 pounds and had a 38-inch waist, your lean body mass would be:

  (200 x 1.082) - (38 x 4.15) + 94.42 = 153.12 lbs.

• 3

  Find your body fat percentage by using the formula (body weight - lean body mass) x 100 / (body weight). By using the results from Steps 1 and 2, your body fat percentage would be:

  (200 - 153.12) x 100 / 200 = 23.44 percent

For Women

• 4

  Weigh yourself on a scale. Then wrap a tape measure around your middle --- at the point where your belt would go --- to find the circumference of your waist. Measure the widest point of your wrist, hip and forearm to find your wrist, hip and forearm circumferences.

• 5

  Multiply your body weight by 0.732 and add 8.987. Formula: (body weight x 0.732) + 8.987. For example, if you weigh 200 pounds, your answer would be (200 x 0.732) + 8.987 = 155.387

• 6

  Divide your wrist circumference by 3.14. For example, if your wrist circumference was 6 inches, your answer would be (6)/(3.14) = 1.91.

• 7

  Multiply your waist circumference by 0.157. For example, if your waist measurement is 12 inches, your answer would be (12) x (0.157) = 1.884.

• 8

  Multiply your hip circumference by 0.249. For example, if your hip measurement is 10 inches, your answer would be (10) x (0.249) = 2.49.

• 9

  Take your forearm measurement and multiply it by 0.434. For example, if your forearm circumference is 10 inches, your answer would be (10) x (.434) = 4.34.

• 10

  Add the results found in Steps 2 and 3 together: (155.387) + (1.91) = 157.297

• 11

  Subtract the results from Step 4 from the results of Step 7: (157.297) - (1.884) = 155.413

• 12

  Subtract the results from Step 5 from the results of Step 8: (155.413) - (2.49) = 152.923

• 13

  Add results from Step 6 and 9 together: (4.34) + (152.923) = 157.263

  The result represents your lean body mass (LBM).

• 14

  Subtract your LBM from your total body weight. Multiply the answer by 100 and divide by your total body weight. Use the answer found in step 10 and a body weight of 200 pounds to solve for your LBM.

  Formula:

  (body weight - lean body mass) x 100 / (body weight).

  Body Fat Percentage (women):

  (200 - 157.263) x 100 / (200) = approx. 21.37 percent body fat.