Adjust Rows and Columns to Fit Ratio of a 8.5 x 11 Sheet of Paper

I am having a hard time wrapping my head around this one. I am basically trying to create a template that i can fill out and print onto a sheet that i have to fill out by hand. I am not going to reproduce the entire sheet because then it would not be the official document we have to turn in. My thought is, to layout an excel document and line up the cells to best match the physical document so when i fill it out, it will print in the appropriate places onto the real document i need to fill out.

I know i need at least 60 columns and 50 rows to have enough cells to work with (can be more if need be for the proper ratio). My question is, is there a way to evenly adjust the row height and column width to match the ratio of a 7.5" x 10" paper (8.5x11 with 1" margins). I could do trial and error by adjusting it, printing it, checking it to original, repeat....but that would waste a lot of paper.

I forgot to add: I want the layout to be in landscape so the 60 columns will be along the 11" side of the paper.