This formula seems to be amazingly accurate.
For Men:
Before you use the formulas, there are two measurements that are required:
Measurement 1: Bodyweight
Measurement 2: Waist Girth (measured at the umbilicus)
Procedure:
1) Multiply your bodyweight by 1.082. Add the result to 94.42. Once your calculation is complete, save the number. à (Bodyweight x 1.082) + 94.42=Result 1
2) Multiply your waist girth by 4.15. Once you get this result, subtract it from the number obtained in step 1 (ie: Step 1 result-Step 2 result). The result obtained after the subtraction is done is your lean bodyweight (your weight if you had no fat in your body at all). à Result 1 - (Waist Girth x 4.15)= Lean Body Weight
3) Finally, subtract your lean bodyweight from your total bodyweight (Total weight-Lean Bodyweight). Once you get the result, multiply that number by 100. Once you get the result divide it by your total bodyweight. This final result is your percentage of body fat. à ((Total Bodyweight - Lean Bodyweight) x 100) divided by (Your Body Weight) = Your Percentage of Body Fat.
Example:
I weigh 190 and I have a 30.5inch waist. Therefore, step 1 is (190 x 1.082) + 94.42 = 300. Step 2 says that my lean body weight equals 300-(30.5 x 4.15)=173.425. Finally, Step 3 says that my body fat percentage is ((190-173.425) x 100) divided by 190= 8.72%.