Trying to create a Sales Projection/Forecast/Estimate

[Guest]

I'm trying to create a estimated sales pace for the month at my restaurant
from a chart that has our daily sales in it.

The current chart has the following formula "=(C38/COUNT(C6:C36))*31" in
cell C42. This formula takes cell C38 which is the TOTAL SALES for the month
using the formula "=SUM(C6:C36)". This formula takes the DAILY SALES from C6
to C36 and obviously adds them up. Our daily sales vary greatly, as on the
weekends we do double to triple our weekday business.

Right now the formula is giving us the same number as our sales total for
the month which from prior experience is probably off by about 27 thousand
dollars.

According to what I can tell the COUNT function allows 1 to 30 arguments is
this what is causing the problem? And how do I create a solution?

Software: Excel 2000
O/S: Windows 2000

 

[Guest]

If you have zeros or formulas that evaluate to zero in column C for the
future days in the month, the COUNT() function will still count them. Thus,
you are taking your total sales so far, dividing by 31, then multiplying by
31, leaving you with your total sales for the month.

Try using =COUNTIF(C6:C36,">0")

 

[Dave Peterson]

My first guess is that you have calculation set to manual.

tools|options|calculation tab.

And the 30 arguments isn't a problem for your formula. It refers to things
like:

=count(a1,a2,a3,b1,b2,b3,....)

=count(c6:c36) is just using one argument.

===
My second guess is that some of your numbers aren't really numbers--they're text
masquerading as numbers.

What do you get when you put =count(c6:c36) in another cell?
what do you get when you put =counta(c6:c36) in another cell?

If you think all your values are numbers, do these formulas match?

 

[Dave O]

Your formula (C38/COUNT(C6:C36))*31 takes the average daily sales and
multiplies by the number of days in the month, which is why it matches
the total sales amount.

If you have a date associated with each daily sales figure, you might
use the WEEKDAY function to sum sales for each Monday, each Tuesday,
etc. This would show how each day contributes to your total monthly
sales figure, and (from a marketing perspective) would provide
visibility as to what day you might have a sales promotion.

For instance: to get total sales for all Sundays:
=SUMPRODUCT(--(WEEKDAY(B6:B36)=1),C6:C36)
.... assuming your dates are in B6:B36.

Note the sum of these numbers will still add up to your total sales
figure; from here you can apply historical percentages of sales
increase / decrease (if you have that data) to make projections.