Centering Wizard (Excel)
I made this little spreadsheet for calculating centering on a card. To make it simpler for me, I converted the centering into a whole number. 50/50 = 1.00 and 80/20 = 4.00, for example. The only thing that breaks it is 100/0 or worse centering, in which case what is the point? You can measure in any unit you like so long as you're consistent. I used a loupe with mm markings, but you could just as easily use pixels. If you use standard measuring units such as 17/64 for example, that works too so long as you type '=17/64' in the cell. To avoid rendering the spreadsheet unusable, be sure to only enter text in the "Units" column. I typed in the scale based on the grading standards listed on PSA's website. Hopefully someone gets use of this.
The N8 Collection: PSA Registry Sets & Showcases