Question: how to calculate planned percentage complete in excel?
Answer: =A2+600/3 our initial estimate of the end date.In C2 we enter today's date and in D2 we enter the total progress to date. (Both C1 and D1 can be updated daily.) ... 
=D2/600 This is our percent complete. ... 
=D2/(C2-A2)
=TODAY()+(600-D2)/E2 Here is a sample: