Tableau Table Calculations

Table calculations compute values based on what is already in your chart — not from the original database. They run after the data arrives in your view and perform comparisons like running totals, percent of total, and rank. Regular calculated fields compute row by row from the raw data. Table calculations compute cell by cell from the visible chart data.

The Key Difference: Regular vs Table Calculation

Analogy: Exam Results

Raw Data (from database):
Student | Score
Alice   | 85
Bob     | 72
Carol   | 90
David   | 68

Regular Calculated Field — works from the database:
"Pass/Fail" = IF [Score] >= 70 THEN "Pass" ELSE "Fail" END
→ Applied to each raw row individually

Table Calculation — works from the chart's visible totals:
"Rank" = RANK(SUM([Score]))
→ Applied after Tableau sums scores and shows them in the chart
→ Carol = Rank 1, Alice = Rank 2, Bob = Rank 3, David = Rank 4

Adding a Quick Table Calculation

The fastest way to use table calculations is through the right-click menu. Right-click any Measure pill on a shelf or in the view. Select "Quick Table Calculation." A submenu shows the available types. Click one and the chart updates instantly.

Available Quick Table Calculations

Running Total Example

Diagram: Monthly Sales vs Cumulative Sales

Month  | Monthly Sales | Running Total
Jan    |    $500       |    $500
Feb    |    $700       |   $1,200
Mar    |    $400       |   $1,600
Apr    |    $900       |   $2,500
May    |    $600       |   $3,100

Monthly Sales → shows each month's result
Running Total → shows total accumulated so far

Line chart of Running Total = always going up
Useful for tracking: "Have we hit $3,000 yet?"

Computing Along: Table Across vs Down

Table calculations have a direction — they can compute across rows (left to right) or down columns (top to bottom). Right-click the measure pill and select "Edit Table Calculation" to change this. The direction determines which values the calculation compares.

Diagram: Compute Direction

Table — Region in Rows, Quarter in Columns

         Q1   Q2   Q3   Q4
East    | 100 | 110 | 90  | 120 |
West    | 80  | 95  | 100 | 85  |
South   | 70  | 75  | 80  | 65  |

Compute Along COLUMNS (Table Across):
Percent Diff Q2 vs Q1 for East = (110-100)/100 = 10%
→ "How did this quarter compare to last quarter?"

Compute Along ROWS (Table Down):
Percent Diff West vs East for Q1 = (80-100)/100 = -20%
→ "How does this region compare to the one above?"

Percent of Total

Apply Percent of Total to show each value as a share of the grand total. In a bar chart of sales by product, each bar converts from a dollar amount to a percentage. All bars now add up to 100%. This is cleaner than a pie chart for many categories.

Example: Before and After

Before (SUM):                After (% of Total):
Furniture    $1,200           Furniture    30%
Technology   $1,800           Technology   45%
Office Sup.  $1,000           Office Sup.  25%
Total        $4,000           Total       100%

Rank Calculation

Apply Rank to order items from highest to lowest automatically. Dragging "Rank" from Analytics or using Quick Table Calculation → Rank numbers each item. Sort the chart by Rank to show a top-N style leaderboard. Combine with a filter to show only the top 10.

Writing Table Calculations in the Formula Editor

You can write table calculations directly using functions like RUNNING_SUM(), RANK(), INDEX(), SIZE(), FIRST(), LAST(), and LOOKUP().

Common Table Calculation Functions

RUNNING_SUM(SUM([Sales]))
→ Cumulative sum from the first row to the current row

RANK(SUM([Sales]))
→ Rank of the current row among all rows

INDEX()
→ Sequential position of the current row (1, 2, 3, ...)

SIZE()
→ Total number of rows in the partition

LOOKUP(SUM([Sales]), -1)
→ Returns the Sales value of the previous row

LOOKUP(SUM([Sales]), FIRST()-INDEX())
→ Returns the Sales value of the very first row

Partitioning and Addressing

Every table calculation runs within a defined group called a partition. It computes separately within each partition. Addressing defines which direction (across or down) the calculation runs within each partition. For example, compute Running Total separately for each Region — Region is the partition — running month by month — Month is the addressing direction.

Summary

Table calculations compute from the chart's visible data, not the raw database. Running Total accumulates values over time. Percent Difference shows growth. Percent of Total converts amounts to shares. Rank orders items by value. All these run via Quick Table Calculation from a right-click. For advanced control, write formulas using functions like RUNNING_SUM(), RANK(), and LOOKUP() in the calculated field editor. Partition and address settings define which group the calculation runs within and in which direction.