When losing fat it is important to know not just how much weight you are losing but how much of your body is muscle and how much is fat. You want to lose fat while maintaining or even building muscle. So, you need some way to keep track of your body fat percentage.
The following are two simple methods to determine current body fat percentage and lean mass percentage.
Method Number One
For this test you will need someone's help and a ruler that reads in millimeters (mm).
Step 1 - Hang your right arm at your side and have someone find the point halfway between your shoulder and elbow, on the rear (triceps side) of your arm.
Step 2 - With his/her thumb and forefinger have him/her pinch a fold of skin and fat away from the muscle.
Step 3 - Have him/her measure the thickness of the skin pinched. (Do not rest the ruler against the skin.)
Step 4 - Have him/her do steps 2 and 3 several times and get the average reading.
Step 5 - Find your body fat percentage by using the chart below.
Fat Percentage Chart
Skin Fold Thickness In MM = % for Men & Women
6mm = 5-9% for men 6mm = 8-13% for women 13mm = 9-13% for men 13mm = 13-18% for women 19mm = 13-18% for men 19mm = 18-23% for women 25mm = 18-22% for men 25mm = 23-28% for women 38mm = 22-27% for men 38mm = 28-33% for women
Method Number Two
This test requires a scale and a tape measure. Do the following calculations:
For Men
Lean body weight = 94.42 + 1.082 (nude weight in pounds) - 4.15 (waist girth around bellybutton in inches)
Then:
Body fat (%) = bodyweight - lean bodyweight x 100/bodyweight
For Women
Lean body weight = 8.987 + 0.732 (weight in kilograms) + 3.786 (wrist diameter in centimeters) + 0.434 (forearm circumference in centimeters)
Then:
Body fat (%) = bodyweight - lean bodyweight x 100/bodyweight
Notes:
To convert pounds to kilograms divide by 2.2
To convert inches to centimeters divide by 0.394
Divide circumference by 3.14 (pi) to get diameter.