Here is a very simply, quick & easy to use google spreadsheet to check & see which how many 4* and 5* heroes you are ready to ascend and what items you need for the rest. 
Instructions for how to fill in the spreadsheet can be found at the bottom of the page.
This is based on a spreadsheet found here on the forum a while back, unfortunately I can’t find the original post to give the creator due credit - if someone knows who it was, please let me know - Happy to give credit where it’s due!