calculating progress

[TRACYJO]

Im working on something that will show progress of production. I want to show percentage complete between two dates. Im using =(DATEDIF(E10,TODAY(),"d")+1)/(DATEDIF(E10,F10,"d")+1) which works fine as long as that line is working within current dates. if its before that date I want it to read 0% but right now it shows #NUM! and after that date it should read 100% but will show 120 or more percent.. how can I fix this?

 

[GlennUK]

=IF(E10>TODAY(),0,MIN(1,(DATEDIF(E10,TODAY(),"d")+1)/(DATEDIF(E10,F10,"d")+1)))