Why Running total in Tableau? - Purpose & Use Cases

The Big Idea

What if you could see your sales adding up automatically, without lifting a finger?

The Scenario

Imagine you have a long list of daily sales numbers in a spreadsheet. You want to see how sales add up over time, but you have to add each day's sales to the total of all previous days by hand.

The Problem

Doing this manually is slow and tiring. You might make mistakes adding numbers, especially if the list is long. Every time new data comes in, you have to redo all the sums again.

The Solution

Using a running total in Tableau automatically adds each value to the sum of all previous values. It updates instantly when data changes, saving time and avoiding errors.

Before vs After

✗ Before

Day 1: 100
Day 2: 100 + 150 = 250
Day 3: 250 + 200 = 450

✓ After

RUNNING_SUM(SUM([Sales]))

What It Enables

It lets you quickly see how numbers build up over time, helping you spot trends and make better decisions.

Real Life Example

A store manager tracks daily sales to see how revenue grows during a promotion, adjusting strategies based on the running total.

Key Takeaways

Manual addition is slow and error-prone.

Running total automates cumulative sums instantly.

It helps visualize growth and trends over time.

Practice

1. What does the RUNNING_SUM() function do in Tableau?

easy

A. Calculates a cumulative total by adding values step-by-step

B. Finds the average of all values in a column

C. Counts the number of rows in a dataset

D. Filters data based on a condition

Solution

1. Step 1: Understand the purpose of RUNNING_SUM()

   RUNNING_SUM() adds values cumulatively across a sorted dimension, like dates.

2. Step 2: Compare with other functions

   Unlike average or count, RUNNING_SUM() accumulates values step-by-step.

3. Final Answer:

   Calculates a cumulative total by adding values step-by-step -> Option A

4. Quick Check:

   RUNNING_SUM() = cumulative total [OK]

Hint: Think 'running total' means adding values one after another [OK]

Common Mistakes:

• Confusing RUNNING_SUM() with average or count functions
• Thinking it filters data instead of summing cumulatively
• Assuming it resets for each row instead of accumulating

2. Which of the following is the correct syntax to create a running total of Sales in Tableau?

easy

A. RUNNING_SUM(SUM([Sales]))

B. SUM(RUNNING_SUM([Sales]))

C. RUNNING_TOTAL(SUM([Sales]))

D. TOTAL_SUM([Sales])

Solution

1. Step 1: Identify correct function usage

   RUNNING_SUM() wraps an aggregation like SUM() to calculate cumulative totals.

2. Step 2: Check syntax correctness

   RUNNING_SUM(SUM([Sales])) uses RUNNING_SUM(SUM([Sales])) which is valid; others use incorrect or non-existent functions.

3. Final Answer:

   RUNNING_SUM(SUM([Sales])) -> Option A

4. Quick Check:

   RUNNING_SUM(SUM()) is correct syntax [OK]

Hint: RUNNING_SUM wraps an aggregation like SUM inside [OK]

Common Mistakes:

• Using RUNNING_TOTAL instead of RUNNING_SUM
• Placing SUM outside RUNNING_SUM incorrectly
• Using non-existent functions like TOTAL_SUM

3. Given the following daily sales data:

Date | Sales
Jan 1 | 100
Jan 2 | 150
Jan 3 | 200

What is the running total on Jan 3 using RUNNING_SUM(SUM([Sales]))?

medium

A. 200

B. 150

C. 450

D. 100

Solution

1. Step 1: Calculate daily sums

   Sales are 100 on Jan 1, 150 on Jan 2, and 200 on Jan 3.

2. Step 2: Compute running total up to Jan 3

   Running total = 100 + 150 + 200 = 450.

3. Final Answer:

   450 -> Option C

4. Quick Check:

   100+150+200 = 450 [OK]

Hint: Add all previous sales including current date [OK]

Common Mistakes:

• Taking only current day sales instead of cumulative
• Adding only two days instead of three
• Confusing running total with daily sales

4. You created a running total using RUNNING_SUM(SUM([Sales])) but the values reset unexpectedly for each category. What is the likely cause?

medium

A. SUM([Sales]) is incorrect syntax

B. The table calculation is partitioned by category, causing reset

C. RUNNING_SUM() cannot be used with categories

D. Data source has missing sales values

Solution

1. Step 1: Understand table calculation partitioning

   Table calculations like RUNNING_SUM reset when partitioned by a dimension, here category.

2. Step 2: Identify cause of reset

   If partitioning is by category, running total restarts for each category separately.

3. Final Answer:

   The table calculation is partitioned by category, causing reset -> Option B

4. Quick Check:

   Partitioning causes running total reset [OK]

Hint: Check partitioning settings if running total resets [OK]

Common Mistakes:

• Assuming syntax error causes reset
• Believing RUNNING_SUM can't work with categories
• Ignoring partitioning in table calculations

5. You want to show a running total of monthly sales but only for the current year. Which approach correctly applies this filter without breaking the running total calculation?

hard

A. Use RUNNING_SUM(SUM([Sales])) without any filters

B. Apply a regular filter for current year after creating the running total

C. Create a calculated field that sums sales only if year equals current year, then apply RUNNING_SUM

D. Use a context filter for current year before applying RUNNING_SUM(SUM([Sales]))

Solution

1. Step 1: Understand filter order impact

   Regular filters applied after table calculations can break running totals by removing data points.

2. Step 2: Use context filter to limit data first

   Context filters limit data before calculations, preserving running total logic for current year only.

3. Final Answer:

   Use a context filter for current year before applying RUNNING_SUM(SUM([Sales])) -> Option D

4. Quick Check:

   Context filter preserves running total correctness [OK]

Hint: Filter data first with context filter, then run running total [OK]

Common Mistakes:

• Applying regular filter after running total breaks calculation
• Not filtering data, showing all years
• Using calculated field without proper filtering