First you draw your bar and position it on the screen (Obvious).
Then, in Every Tick, you put the formula (TotalCornStored/TotalCorn)* max bar size (Height or width).
It is recommended to use the lerp command to have a smoother transition.
Definitely appreciate your suggestion however I'm pre-newb. When I use this, the blue progress bar just ping pongs.
+ System: Every tick
-> System: Set TotalCornSpace to int(TotalCorn)-int(TotalCornStorage)
-> CornStorageBar: Set progress to TotalCornSpace