How to Figure Body Mass Index in Percentages

Body mass index (BMI) is an approximate measurement of a person's body fat based on height and weight. While you can compare your BMI score to charts that show healthy guidelines, you may want to correlate your score to an actual percentage. Figuring your BMI is terms of percent can give you a fairly accurate idea of your actual percentage of body fat.

Things You'll Need

• Height measurement
• Weight measurement
• Calculator

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Instructions

• 1

  Figure your BMI using this formula: (weight (pounds) / [height (inches)]^) x 703. For example, if you are a man who is 72 inches tall, square 72 to get 5,184. If you weigh 185 pounds, divide 185 by 5,184 to get 0.0357. Multiply 0.0357 by 703 to get a BMI of 25.1.

• 2

  Multiply your BMI by 1.2. For example, 25.1 x 1.2 = 30.12.

• 3

  Multiply your age times 0.23. If you are 40, multiply 40 by 0.23 to get 9.2.

• 4

  Add the answers from Steps 2 and 3. For example, 30.12 + 9.2 = 39.32.

• 5

  Subtract 10.8 from the answer in Step 4 if you are a man. In this example, 39.32 - 10.8 = 28.52. If you are a woman, do not subtract anything. Carry your answer from Step 4 to Step 6.

• 6

  Subtract 5.4 from your answer in Step 4 for women; men should subtract 5.4 from the answer in Step 5. For example, 28.52 - 5.4 = 23.12. This means your body fat is 23.12 percent.