That's easy. Get a piece of paper and make 4 columns
First column header % - 2nd column 15' scale - 3rd 25' scale and so on.
Down the first column write 100%, next line down 90%, next 80% like so down to 10%.
Next to the 100% row write scale distance.
100% 15' 25' 50' 100' 150'
90% 13.5' 22.5' 45' 90' 135'
80%
70%
60%
Break it out to 95% 85% to if you think you need it.
Hope that's what you're talking about.
EDIT,,, What I should have added is that you'll need some kind of percent ruler for the meter. Putter pal works but you can also use a piece of paper with the proper markings.
What you could do is buy the cheapest putter pal and trace the markings on the paper. Of course, you'll have to adjust for the different green speeds