Plot Scale is a subsidiary application for AutoCAD. It is a program that will help you adjust the Plot Scale column, on which depends the scale of the drawing directly. It will also help you draw a border to a determined scale. Additionally, it will also give you information about how 1cm in real life translates to your PC drawing.
Firstly, you must find the drawing´s dimension line. Then you have to choose the "distance" option to measure its real size. Insert it in "actual size". The following step is to place the dimension line scale into "dimension line" and choose the unit of measurement, the scale required, and click on Plot Scale. Take the obtained results, place them in AutoCAD and your drawing will be automatically redimensioned.