This doesn't work for my data. I tried this approach already. It might work
if each month's sales were fairly equal. The variance between months is too
great. For my example, I got 9.23 when I know the result should be 4.5 or at
its basic using full cells, 5. Thanks for the help though.

"Shane Devenshire" wrote:

Hi,

Suppose last years number are in A1:A12 (Jan-Dec) and your current supply is
in B1

=12*B1/SUM(A1:A12)

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If this helps, please click the Yes button

Cheers,
Shane Devenshire


"JLewis" wrote:

I have a spreadsheet with current inventory on hand and the sales for each
month from the last year. I want to figure how many months our inventory on
hand will last based on the last years sales. For instance, WidgetA has 100
on hand and Mar, Apr, May, Jun & Jul sales were 5,10,15,40,60, respectively.
I know that we have 4.5 months supply, but I have to manually figure this
calculation. I have more than 400 items. This takes a long time to figure, is
there any way to automate the figuring of the months supply?