Enter the perimeter of the contour around the area and the total area into the calculator to determine the shape factor.

Shape Factor Formula

The following equation is used to calculate the Reverse Saturation Current.

SF = P / SQRT(A)

  • Where SF is the shape factor
  • P is the perimeter of the contour around the area
  • A is the total area

What is a Shape Factor?


A shape factor ratio is a measure of the length of a perimeter relative to the square root of the area that perimeter surrounds.

How to Calculate Shape Factor?

Example Problem:

The following example outlines the steps and information needed to calculate Shape Factor.

First, determine the length of the perimeter. In this example, the length of the perimeter is measured to be 200 ft.

Next, determine the area. In this example, the area is calculated to be 500 ft^2.

Finally, calculate the shape factor using the formula above:

SF = P / SQRT(A)

SF = 200 / SQRT(500)

SF = 8.994