Formula to calculate project target

[99problems]

Hello


I am trying to calculate my project target using the below formula.

Completed	Target	Start Date	End Date
100%	=IFERROR(1-(R1-NOW())/(R1-Q1),100%)	06-01-15	06-15-15

This will not work when i apply this formula today. Because my formula has NOW() so it will return the today's date and calculate. But the project end date is already passed and it is completed. So when it is completed i do not want it to calculate the target, how is this possible?

Thanks

[JohnTopley]

In cell formatted as %

=IFERROR(IF(R1>NOW(),1-(R1-NOW())/(R1-Q1),1),1)

Result will be 100% if completed.

[99problems]

In cell formatted as %

=IFERROR(IF(R1>NOW(),1-(R1-NOW())/(R1-Q1),1),1)

Result will be 100% if completed.

thanks. it works!