=if(a1="R",5,if(a1="L",7,if(a1="C",10,"input error")))
If you've got more than three or four such conditions, you'll be better
served by using a vlookup.

"MikeL" wrote:

I would like to write a formula that looks at one cell and sees if there is a
certain letter, R, L or C. and depending on what letter is there it would add
so many days to another date. I am sure I did it before but I do not
remember how I did it. Can anyone help?