Math CentralQuandaries & Queries


Question from Brian:

I have no problem calculating year over year net profits but am having trouble when it comes to a negative.
2007 Net Profit = -110,333.00
2008 Net Profit = 66,054.00

I am coming up with 159.87% increase in 2008 over 2007 using the same formula as if all were positive number, but it does not look right?
Your assistance would be appreciated!


I agree, it doesn't look right.

Suppose in 2007 the loss hadn't been so great, only -10,333.00, then the formula you used gives a 739% increase in 2008 over 2007.

The increase of $176,387.00 from -$110,333.00 to $66,054.00 is a meaningful number but to attempt to express it as a percentage increase is meaningless. Percentage increase should only be used when the beginning and ending numbers are both positive.


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