Calculating Percentage Completed using Dates

[PCB Designer]

Hello All,
I am very new to using formulas within excel. I have a excel document with a start date, estimated completion date and an actual completion date. I have a column labeled On Time Percentage. I would like to
calculate the On Time Percentage of the start date, estimated completion date and an actual completion date. I am lost trying to figure this out.

 

[Joe4]

Welcome to the Board!

I am not sure if your question is quite clear. I thought you wanted an overall completion percentage (one number calculated from all records), but you show the "On Time Percentage" on each row, suggesting that maybe each record has its own completion percentage. In that case, you would need to explain to us exactly how you want this value calculated. What is the logic you want to use?