"Mel" wrote:
(+Budget/Actual)-1
((Actual - Budget)/Budget)

The first formula is effectively (budget-actual)/actual.
Conversely, the second formula is effectively
(actual/budget)-1.

Now you can see the difference. The first formula is the
percentage difference between "budget" over "actual".
The second formula is the percentage difference between
"actual" over "budget".

The second formual is typically what want in this context.
It answers the question: "what percentage over-budget
are we?".

But if you change the names, both formulas might be
equally valid, depending on what you want. For example,
if "budget" is "myDistance" and "annual" is "yourDistance",
the first formula answers the question: "what percentage
more (or less) did I travel?"; and the second formula
answers the question: "what percentage more (or less)
did you travel?".

HTH.