Custom table calculation scope in Tableau - Step-by-Step Guide

Introduction

Custom table calculation scope lets you control how Tableau calculates values across your data. It helps you decide which parts of your table to include when doing calculations like running totals or percent of total.

When you want to calculate a running total only within each region, not across all regions.

When you need to show percent of total sales by category but reset the total for each year.

When you want to rank products within each category separately.

When your dashboard needs to compare values across columns but not rows.

When you want to customize how subtotals or grand totals are calculated in a table.

Steps

Step 1: Right-click

- the measure field in the view

A menu appears with calculation options

💡 Make sure your measure is already in the view

Step 2: Select

- Add Table Calculation

The Table Calculation dialog box opens

Step 3: Choose

- Calculation Type dropdown

You see options like Running Total, Percent of Total, Rank, etc.

Step 4: Click

- Customize button next to Compute Using

Options to set the scope and direction of the calculation appear

Step 5: Select

- Specific dimensions or Table (Down, Across) options

Tableau adjusts how it calculates the values based on your selection

💡 Use 'Specific Dimensions' to pick exactly which fields define the calculation scope

Step 6: Click

- OK button

The table calculation applies with your custom scope

Before vs After

Before

Running total calculated across all rows ignoring regions, showing cumulative sales for all data combined

After

Running total calculated separately within each region, showing cumulative sales restarting at zero for each region

Settings Reference

Calculation Type

📍 Table Calculation dialog box

Defines the type of calculation Tableau performs on the data

Default: Running Total

Compute Using

📍 Table Calculation dialog box

Controls the direction and scope of the calculation across the table

Default: Table (Down)

Specific Dimensions

📍 Compute Using options in Table Calculation dialog

Lets you pick exactly which dimensions define the calculation scope

Default: All dimensions checked

Common Mistakes

Not setting the calculation scope correctly, causing totals to run across the entire table instead of within groups

This leads to misleading results because the calculation ignores natural data groups like regions or categories

Use 'Specific Dimensions' in Compute Using to limit the calculation to the desired groups

Choosing the wrong direction (Down vs Across) for the calculation

The calculation may run horizontally when you expect it vertically, or vice versa, causing incorrect results

Understand your table layout and select the Compute Using option that matches the direction of your data

Summary

Custom table calculation scope controls which parts of your data Tableau uses for calculations.

You can choose specific dimensions and directions to get accurate running totals, ranks, and percentages.

Always check your calculation scope to avoid misleading results in grouped data.