I am trying to work out the percentage difference between two numbers (one of which is negative), NOT PERCENTAGE CHANGE. I have done quite a bit of reading, but there doesn't appear to be a definitive answer. Where both numbers are positive, I have been using the formula listed on the following site (). If both numbers are negative, I simply input the absolute values, making them positive. I have issues arise when one of the numbers is negative - for instance:
The percentage difference between 1.6 and -8.8. If I use the formula in the link above, it provides me a result of -293%, but I'm not sure if this is correct - from a methodological stand point. Is this something that would be frowned upon in the mathematics world?
Cheers, Bosshard
$\endgroup$ 31 Answer
$\begingroup$The percentage difference is defined as the difference of the values, divided by the average and written in percentage. If you have two values, the formula is$\frac{|x-y|}{\frac{x+y}{2}} \times 100$. This also holds for negative numbers.
Remark:
(1) It is better known as relative change in percentage, for example here .
