Disclosed is a system and method for dynamically designing a custom product. The method is initiated using custom software, which permits user interaction via a graphical user interface. An HTML drawing element is provided in a display area of the graphical user interface, configured to display graphics drawn using a program executable by the computing device, the program comprising instructions to draw the custom product as a plurality of line segments. The program is executed to render the plurality of line segments, which are displayed as a first displayed version of the custom product in the display area. A length dimension value is received in an entry field of the display interface, to update one or more of the line segments. The program is re-executed to render the updated line segments, which are displayed as an updated displayed version of the custom product in the display area.