Convert 1-5 Grading Scale to 1-100 Grading System I am creating a formula in Excel to convert 1-5 Grading Scale to 1-100 Grading System Suppose that I have the following table:
97-100 = 1.00
94 - 96 = 1.25 
91-93 = 1.50 
88-90 = 1.75 
85-87 = 2.00 
82-84 = 2.25 
79-81 = 2.50 
76-78 = 2.75 
75 = 3.00
My problem is this: What if the grade is 1.47, what will be the exact numerical equivalent from 91-93? And how do I compute it?

This is an answer based more on intution. Hopefully, it will be easier to understand.
You can multiply the score in the ratio of their respective range.
So, since the ratio will be $\frac{100}{5}=20$.
Let $S_5$ and $S_{100}$ be the respective scores.
Therefore,
$$S_{100}=S_5 \times 20$$
However, I included $0$ here. For no $0$ values, we essentially have to convert a $0$ to $4$ scale to $0$ to $99$.
We can do this by
$$S_{100}=(S_5-1)\times\frac{99}{4}+1$$
Now you can just plug in the values to find whatever you like.
