Abstract: Device and related method for determining the surface area of a wound. The device includes a transparent sheet having a series of perforations defining first and second sections of the sheet which allow the first and second sections to be separated from one another along the perforations. The transparent sheet is folded along the perforations so that the two sections overlap each other, and the sections are substantially free of adhesive material. The second section includes indicia thereon which allow a user to determine the surface area of a wound after the outline of the wound or opening is traced thereon. Upon use, the device is placed over the wound or opening, with the first section toward the wound or opening, and the outline of the wound or opening is traced onto the second section.