Ok. So I can see the percentage of what was taken (actual). If this was
less than forecast, I would expect to see a figure such as 75%. If it was
more than the forecast, I would expect to see a figure such as 131%. Or, as
descibed, 31% more than forecast.

Forecast 'accuracy' though.

If forecast=50 and actual=50, then this was 100% accurate.

If forecast=50 and actual=60, then this was not 120% accurate. The value
should be less than 100%, do you see what I mean?

"vezerid" wrote:

Dave,

First, if you examine the accuracy of the forecast, it must stay in the
denominator.
Second, why are you troubled with percentages greater than 100? A 131%
means exactly this: that the actual was 31% more than the forecast.

The second formula I gave you essentially is maybe better for your
thinking. It would return
-25% for a lower actual and +31% for a higher actual. Both are
percentages on the forecast.

Does this help?
Kostis