The Body Fat Calculator
can be used to estimate your total body fat based on specific measurements. Use the "Metric Units" tab if you are more comfortable with the International System of Units (SI). To get the best results, measure to the nearest 1/4 inch (0.5 cm). This calculation is based on the U.S. Navy method, but also includes the calculation of body fat percentage using the BMI method (both of which are outlined below).

 
Body fat percentage (BFP) formula for males:
USC Units:
BFP = 86.010×log10(abdomen-neck) - 70.041×log10(height) + 36.76
SI, Metric Units:
BFP = 
495
1.0324 - 0.19077×log10(waist-neck) + 0.15456×log10(height)
- 450
Body fat percentage (BFP) formula for females:
USC Units:
BFP = 163.205×log10(waist+hip-neck) - 97.684×(log10(height)) - 78.387
SI, Metric Units:
BFP = 
495
1.29579 - 0.35004×log10(waist+hip-neck) + 0.22100×log10(height) 
- 450

Note that the results of these calculations are only an estimate since they are based on many different assumptions to make them as applicable to as many people as possible. For more accurate measurements of body fat, the use of instruments such as bioelectric impedance analysis or hydrostatic density testing is necessary.

Fat mass (FM) formula:
FM = BF × Weight
Lean Mass (LM) formula: 
LM = Weight - FM