Can anybody tell me if this will give more speed to mi file :

I have this formula in 3 columns for 12 months & for 85 rows down & in 4
worksheet in the same file, this makes aprox 12 K cells that have the
formula, but it is loading the actual by month, example, I have Jan Actual &
rest of the Year 0.00,

Right now I have this:
=IF(ISERROR(VLOOKUP(" "&$B6,Xsears2,2,FALSE)), ,VLOOKUP("
"&$B6,Xsears2,2,FALSE))
This just goes & graves the units sold in a table "xsears2 for a part number
in B6
and returns a 0.00 if nothing is found.

Right now it takes a wile to calculate & I was wondering if this could make
it faster

=IF(G4=" ",0,(IF(ISERROR(VLOOKUP(" "&$B5,Xsears2,2,FALSE)), ,VLOOKUP("
"&$B5,Xsears2,2,FALSE))))

If I input actual into G4 this will activate the formula, if no actual it
will just return 0.00, Please can someone help me, I really dont want to
change the formulas in all of my worksheets