The problem:

The client wants:

Percent of total sales for each region compared to ALL regions,

even when Region is filtered.

However, the calculation currently behaves like a table calculation:

SUM([Sales]) / TOTAL(SUM([Sales]))

This recalculates the total after Region filters are applied, so removing a region changes the denominator.

Tableau Documentation — How to prevent recalculation:

To keep percent-of-total unchanged when filtering, Tableau’s recommended method is to use FIXED LOD expressions to lock the granularity.

Two values must be fixed:

Numerator: Sales for that specific region{ FIXED [Region] : SUM([Sales]) }

Denominator: Total sales across all regions, independent of filters{ FIXED : SUM([Sales]) }(FIXED with no dimension = entire data set)

Then compute the percentage:

{ FIXED [Region] : SUM([Sales]) } / { FIXED : SUM([Sales]) }

This ensures:

The region sales remain accurate.

The overall total remains constant, even if filters remove regions.

Region filtering no longer recalculates percent-of-total.

Why the other options are incorrect:

A. {FIXED [Region]: SUM([Sales])} / SUM([Sales])

The denominator is still affected by filters → recalculates % of total.

B. {FIXED [Region]: SUM([Sales])} / { [Sales] }

{[Sales]} is not valid syntax and does not fix granularity.

D. {FIXED [Region]: SUM([Sales])}

This gives only the numerator — no percent-of-total calculation.

The only correct LOD solution is option C.

Tableau LOD Expression Guide: FIXED for filter-independent calculations.

Tableau Percent-of-Total Best Practices: use FIXED LOD to avoid recalculation when filters change.

Order of Operations: FIXED LODs occur before dimension filters, keeping totals stable.