Imperial:

 Weight in Pounds / ( Height in inches x Height in inches ) x703

Metric:

 Weight in Kilograms / ( Height in Meters) ²

Imperial Women:

655 + ( 4.35 x weight in pounds ) + ( 4.7 x height in inches ) - ( 4.7 x age in years )

Imperial Men:

66 + ( 6.23 x weight in pounds ) + ( 12.7 x height in inches ) - ( 6.8 x age in year )

Metric Women:

655 + ( 9.6 x weight in kilos ) + ( 1.8 x height in cm ) - ( 4.7 x age in years )

Metric Men:

66 + ( 13.7 x weight in kilos ) + ( 5 x height in cm ) - ( 6.8 x age in years )

Factor 1:

(Total body weight x 0.732) + 8.987

Factor 2:

Wrist measurement (at fullest point) / 3.140

Factor 3:

Waist measurement (at naval) x 0.157

Factor 4:

Hip measurement (at fullest point) x 0.249

Factor 5:

Forearm measurement (at fullest point) x 0.434

Lean Body Mass:

Factor 1 + Factor 2 - Factor 3 - Factor 4 + Factor 5

Body Fat Weight:

Total bodyweight - Lean Body Mass

Body Fat Percentage:

(Body Fat Weight x 100) / total bodyweight

Factor 1

(Total body weight x 1.082) + 94.42

Factor 2

Waist measurement x 4.15

Lean Body Mass

Factor 1 - Factor 2

Body Fat Weight

Total bodyweight - Lean Body Mass

Body Fat Percentage:

(Body Fat Weight x 100) / total bodyweight

Waist to hip ratio:

Waist Circumference / Hip Circumference