Calculated measure items are based on expressions that you set up in the Expression window. The measure items are calculations between pieces of data or groups of data. They can represent additions, subtractions, multiplications, divisions, etc. And, their expressions can be built using regular measure items, other calculated measure items, measures, members, named sets, and special functions such as an average, variances, and percent of total.
Calculations for a calculated measure item are executed for each member of a level. A calculated measure item with its Distinct property enabled is known as a distinct calculated data item, and the calculations for that type of measure item are executed once for each level rather than individually for each level member. In the following view, Var % YTD 2012vs 2013 is a calculated measure item that is executed for Division F and G. The last measure item, % of Total 2013, is a distinct calculated measure item performed for the overall Division level.