This paper explains the Aircraft Preliminary Sizing Tool (PreSTo) developed at the Hamburg University of Applied Sciences. From the different modules of PreSTo, PreSTo wing, and its sweep angle have been taken as the key feature to explain further. In order to figure out the necessary values for the double trapezoidal wing a loop has been created between the kink chord, inner taper ratio, inboard leading edge sweep angle, and inboard 25 % chord sweep angle. By the end of the loop all the major chords, sweep angles, and taper ratios are calculated and a 2D representation of the wing is given. PreSTo will interact with the user by giving suggestions and during certain parameter conflicts; it can give warning to the user concerning his previous made design choices. Values of wing parameters generated in the wing module are finally stored into PreSTo central database. OpenVSP Connect retrieves values from PreSTo central database and visualizes the aircraft and its wing in 3D with NASA’s tool Open Vehicle Sketch Pad (OpenVSP).