The Parillo 9-Site equation is used to calculate the percentage of body fat that does not consider gender or age, and it's ideal for the general population. However, due to its simplicity it tends to have a good margin of error and inaccurate results.
To calculate body fat percentage with the Parillo method, take the skinfolds measurements (in millimeters) and perform the following equation. The formula is the same for men and women.
Percentage of body fat (%) = (27 x sum of all skinfolds) / body weight (lbs.)