Creating calculated fields in Tableau - Dashboard Building Guide

Dashboard Mode - Creating calculated fields

Business Question

How can we calculate total sales and average sales per order to better understand our sales performance?

Sample Data

Order ID	Product	Quantity	Unit Price	Sales Region
1001	Notebook	2	15	North
1002	Pen	5	3	South
1003	Binder	1	10	East
1004	Pen	10	3	West
1005	Notebook	3	15	North
1006	Binder	4	10	South

Dashboard Components

• KPI Card: Total Sales
  Calculation: SUM([Quantity] * [Unit Price])
  Result: 2*15 + 5*3 + 1*10 + 10*3 + 3*15 + 4*10 = 30 + 15 + 10 + 30 + 45 + 40 = 170
• KPI Card: Average Sales per Order
  Calculation: AVG([Quantity] * [Unit Price])
  Result: Total Sales (170) / Number of Orders (6) = 28.33
• Bar Chart: Sales by Region
  Calculation: Sum of sales per region using calculated field [Quantity] * [Unit Price]
  Data:
  • North: (2*15) + (3*15) = 30 + 45 = 75
  • South: (5*3) + (4*10) = 15 + 40 = 55
  • East: 1*10 = 10
  • West: 10*3 = 30
• Table: Detailed Sales
  Shows all columns plus calculated sales per order [Quantity] * [Unit Price]

Dashboard Layout

+----------------------+----------------------+
|   Total Sales (KPI)  | Average Sales (KPI)  |
+----------------------+----------------------+
|                      Bar Chart: Sales by Region                      |
+---------------------------------------------------------------------+
|                         Table: Detailed Sales                       |
+---------------------------------------------------------------------+

Interactivity

A filter for Sales Region allows users to select one or more regions. When a region is selected, all components update:

• Total Sales recalculates sum for selected regions.
• Average Sales per Order recalculates average for selected regions.
• Bar Chart updates to show only selected regions.
• Detailed Table shows only orders from selected regions.

Self Check

If you add a filter for Sales Region = North, which components update and what are their new values?

• Total Sales: 75 (from orders 1001 and 1005)
• Average Sales per Order: 75 / 2 = 37.5
• Bar Chart: Shows only North region bar with value 75
• Detailed Table: Shows only orders 1001 and 1005

Key Result

Dashboard shows total and average sales with sales by region and detailed order data using calculated sales fields.

Practice

1. What is the main purpose of creating a calculated field in Tableau?

easy

A. To change the color of a chart

B. To import data from external sources

C. To create new data values based on existing data using formulas

D. To delete rows from the data source

Solution

1. Step 1: Understand what calculated fields do

   Calculated fields allow you to create new data by applying formulas to existing data.

2. Step 2: Compare options to this definition

   Only To create new data values based on existing data using formulas describes creating new data values using formulas, which matches the purpose of calculated fields.

3. Final Answer:

   To create new data values based on existing data using formulas -> Option C

4. Quick Check:

   Calculated fields = new data from formulas [OK]

Hint: Calculated fields create new data from old data using formulas [OK]

Common Mistakes:

• Confusing calculated fields with data import
• Thinking calculated fields change visuals only
• Assuming calculated fields delete data

2. Which of the following is the correct syntax to create a calculated field that adds 10 to the value of the field Sales?

easy

A. SUM(Sales) + 10

B. [Sales] + 10

C. {Sales} + 10

D. Sales + 10

Solution

1. Step 1: Recall Tableau field reference syntax

   In Tableau, fields are referenced inside square brackets like [Sales].

2. Step 2: Check each option's syntax

   [Sales] + 10 uses [Sales] + 10, which is correct. Sales + 10 misses brackets, C uses curly braces which are incorrect here, and A uses aggregation which is not needed for simple addition.

3. Final Answer:

   [Sales] + 10 -> Option B

4. Quick Check:

   Field names need brackets in formulas [OK]

Hint: Use square brackets around field names in formulas [OK]

Common Mistakes:

• Omitting square brackets around field names
• Using curly braces instead of brackets
• Adding aggregation unnecessarily

3. Given the calculated field formula IF [Profit] > 0 THEN 'Profit' ELSE 'Loss' END, what will be the result for a record where [Profit] is -50?

medium

A. 'Loss'

B. 'Profit'

C. 50

D. Error

Solution

1. Step 1: Understand the IF condition

   The formula checks if [Profit] is greater than 0. If yes, returns 'Profit', else returns 'Loss'.

2. Step 2: Apply the condition to the value -50

   Since -50 is not greater than 0, the ELSE part applies, so the result is 'Loss'.

3. Final Answer:

   'Loss' -> Option A

4. Quick Check:

   Profit > 0? No, so 'Loss' [OK]

Hint: Check IF condition carefully for each value [OK]

Common Mistakes:

• Confusing greater than with less than
• Expecting numeric output instead of text
• Ignoring ELSE clause

4. Identify the error in this calculated field formula: IF [Sales] > 1000 THEN 'High' ELSE 'Low'

medium

A. Incorrect use of square brackets around Sales

B. No error, formula is correct

C. Using text values instead of numbers

D. Missing END keyword to close IF statement

Solution

1. Step 1: Review IF statement syntax in Tableau

   Tableau IF statements must end with the keyword END to close the block.

2. Step 2: Check the given formula

   The formula lacks the END keyword at the end, so it will cause a syntax error.

3. Final Answer:

   Missing END keyword to close IF statement -> Option D

4. Quick Check:

   IF statements need END keyword [OK]

Hint: Always end IF statements with END [OK]

Common Mistakes:

• Forgetting END keyword in IF formulas
• Misplacing square brackets
• Confusing text and numeric outputs

5. You want to create a calculated field that categorizes sales into three groups: 'Low' for sales below 500, 'Medium' for sales between 500 and 1000, and 'High' for sales above 1000. Which formula correctly implements this?

hard

A. IF [Sales] < 500 THEN 'Low' ELSEIF [Sales] <= 1000 THEN 'Medium' ELSE 'High' END

B. IF [Sales] < 500 THEN 'Low' ELSEIF [Sales] < 1000 THEN 'Medium' ELSE 'High' END

C. IF [Sales] < 500 THEN 'Low' ELSEIF [Sales] < 1000 THEN 'Medium' ELSEIF [Sales] > 1000 THEN 'High' END

D. IF [Sales] < 500 THEN 'Low' ELSEIF [Sales] <= 1000 THEN 'Medium' ELSEIF [Sales] > 1000 THEN 'High'

Solution

1. Step 1: Understand the sales ranges

   Sales below 500 = 'Low', 500 to 1000 inclusive = 'Medium', above 1000 = 'High'.

2. Step 2: Check each formula for correct conditions and syntax

   IF [Sales] < 500 THEN 'Low' ELSEIF [Sales] <= 1000 THEN 'Medium' ELSE 'High' END correctly uses ELSEIF with <= 1000 for 'Medium' and ends with END. IF [Sales] < 500 THEN 'Low' ELSEIF [Sales] < 1000 THEN 'Medium' ELSE 'High' END excludes 1000 from 'Medium'. IF [Sales] < 500 THEN 'Low' ELSEIF [Sales] < 1000 THEN 'Medium' ELSEIF [Sales] > 1000 THEN 'High' END has an extra ELSEIF but no final ELSE. IF [Sales] < 500 THEN 'Low' ELSEIF [Sales] <= 1000 THEN 'Medium' ELSEIF [Sales] > 1000 THEN 'High' misses END keyword.

3. Final Answer:

   IF [Sales] < 500 THEN 'Low' ELSEIF [Sales] <= 1000 THEN 'Medium' ELSE 'High' END -> Option A

4. Quick Check:

   Ranges inclusive and END keyword correct [OK]

Hint: Use ELSEIF and END; include boundary with <= for ranges [OK]

Common Mistakes:

• Missing END keyword
• Incorrect boundary conditions (e.g., excluding 1000)
• Using multiple ELSEIF without final ELSE