try this

=IF(A1TODAY(),0,IF(TODAY()=A2,1,(TODAY()-A1)/(A2-A1)))

"John" wrote:

I've been playing with this, but can't get it to work.

I have a product that has a 10 year shelf life. I'd like a spread sheet
that users can open that will calculate the percentage that is left, based
on "Today's date".

I've tried this.

A1 - 7-Jul-2000 (Entered as date)
A2 - 7-Jul-2010 (Entered as date)
A3 - =A2-A1" gives me 3652
A4 - =Today()

And now I'm stuck. Tried a few different things, but I'm getting further
away instead of closer.

Any and all help gratefully appreciated.

TIA
John