How do I find a % difference between two numbers (comparing 2005 .

[Officer Steve]

How do I find the percent difference between two numbers. I am working in a
police department and am comparing our last year 2004 stats to our 2005
stats. I want to use 2005 as the baseline and show either a % increase or %
decrease to 2004 stats. Sometimes I have a zero which throws the forumlas
I've used off.

I would sure appreciate any help on this matter.

Thanks.

 

[Heidi]

Steve,

If you have 2004 in column A, and 2005 values in column B, your formula (in
column C) should look like:

=(B2-A2)/A2

The error you are getting from Excel when you have a zero in the 2004
column is because mathematically, you can't take a % of zero.

So, if you had 0 crimes in 2004 and 3 in 2005, you mathematically can't do
a % change on that. What you could say instead is that there were 3 more
crimes in 2005 than 2004.

Good luck. Hope most of your numbers are negative!

Heidi

 

[Gary L Brown]

Hi Steve,
First off, typically the older stat is the base line. That said, use this
formula, substituting the Cell Coordinates for the years...

=if(2004=0,"",(2005 - 2004)/2005)
or
=if(2004=0,0,(2005 - 2004)/2005)

using 2004 as a base line...
=if(2004=0,"",(2005 - 2004)/2004)
or
=if(2004=0,0,(2005 - 2004)/2004)

Format the cell with the formula as a '%'.

HTH,

 

[joeu2004]

How do I find the percent difference between two numbers.

=(A1-B1)/B1

where column B is "before" (old) and column A is "after" (new).
Remember to format the cell as Percentage if you want "%".

Sometimes I have a zero which throws the forumlas
I've used off.

=IF(B1 = 0, "something", (A1-B1)/B1)

The question only you can answer is: what is "something"?
I like the following:

=IF(B1 = 0, A1, (A1-B1)/B1)

Thus, if B1 is 0 and A1 is 3, the result will be 300%. Purists
will tell you that is wrong: you cannot have a percentage
increase over 0; and mathematically, they are correct. But
the alternative is to display something that is inconsistent
with all other cells where B1 is not zero. If you are okay
with that, fine. I prefer consistency, and I think 300% is
not unreasonable; compare with B1=1 (200%).

 

[lstreet]

Ok but what happens then if you are trying to use the data to predict future
data...let's say for sales projections based on prior year percents of change
and then using the average of those percents of change? If you suddenly have
300% growth this will throw all other years out of alignment and the average
will be way too high.

 

[Spiky]

Ok but what happens then if you are trying to use the data to predict future
data...let's say for sales projections based on prior year percents of change
and then using the average of those percents of change? If you suddenly have
300% growth this will throw all other years out of alignment and the average
will be way too high.

Did you have zero sales last year? I fail to see how this issue will
impact normal calculations, as there would be no need for an altered
formula. Even if you are talking about a business that doesn't exist
yet, perhaps creating a business plan, you will start from actual
assumptions, not $0.

And you do know that the thread is more than 2.5 years old.