Is there a way to test if Excel has recalculated when using Manual Calculation?

I have a fairly large, and somewhat slow sheet which requires a large amount of data entry that is slowed down by excel recalculating after every entry. I've switched to manual calc on F9, which makes things much faster and far more user friendly, but I'd like to add a flag which notifies the user when the sheet has not been recalculated.

I wrote the thing and even I often look at a value thinking there's an error when in fact the sheet just requires recalculating.

So is there something like =IF(CALC=0,"Sheet Requires Recalculation","Sheet is calculated!")?