Advice needed to speed this code.

[p45cal]

But when i have clear all the calculated data i have had to click almost 5 times to have the required results and with a total time of 15.53 secs. Can you please advise as normally with each change down on quantities or minimum qty on an order we will need to clear the previous data before previewing the newly calculated data.

is there a possibility that it do the calculation on one click as to understand if all calculation has been done we will need to check all the orders is are well loaded.

That is just the type of thing I was referring to when I said:

It's taking me too long to work out how calling Block_date_Start_Date interferes, as when this is included (the comment apostrophe removed) we need several iterations (more than 6) for the results to become stable (but still there remain some 15 cells with different results).

The problem is that some of the cells needed to calculate the main part of the grid are themselves dependant on what's in the grid. You need to make sure that all cells which are used in calculating the main grid are NOT dependant on any of the cells in that main grid.