Hi!

The =Sum(IF.....) version is an array formula and in most cases array
formulas take more resources (time to calc, disk space that translates into
larger file size and memory useage) than non-array formulas.

What makes Sumproduct such a robust function is that it accepts arrays as
arguments and in most cases, is more efficient than an array formula. I
guess the general rule of thumb is if you can avoid using an array formula,
do so.

Biff

"qflyer" wrote in
message ...

That works just fine...while I was messing around with it myself, I
found that =SUM(IF((A50:A3000TODAY()-90)*(L50:L30000),H50:H3000))
also works...any ideas on which formula works "best"? They both find
the same answer, but I will be using various forms of the formula in
over 70 cells which are updated constantly when I add in a new flight.
I found that the
=SUM(IF((A50:A3000TODAY()-90)*(L50:L30000),H50:H3000)) formula causes
a slight slow down (recalculating the sheet takes about .5 seconds,
before adding in the new formulas it was immediate) when entering a new
flight.


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qflyer
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