Waterfall charts are a great way to visualise the quantitative change of a numeric measure, either between categories or across a certain time period. It can also be used to show cumulative change. Waterfall charts are simple and easy to interpret, making it a popular choice for corporate dashboards.
How to build a waterfall chart?
For this guide, I will be creating a waterfall chart using the ‘Sample – Superstore’ data source that comes with Tableau.
Step 1: Choose a measure and dimension for your waterfall chart.
I selected the Sales and Order Date fields. Click and drag the measure to the Rows shelf. Then bring the dimension, for which you want to visualise the change of the measure, to the Columns shelf.
Tip: If you are using a date field, you can right click and drag the field to the shelf to show more options. Select one of the Continuous date options, otherwise you might not be displaying all of your dates properly.
I selected MONTH(Order Date) in the Continuous date options.
Step 2: Change mark type to ‘Gantt Bar’.
Step 3: Create a Calculated Field containing the inverse of your measure.
In my example, it is the inverse (or negative) of Sales.
Step 4: Drag the inverse measure onto ‘Size’ in the Marks Card.
Step 5: Apply the ‘Difference’ Table Calculation to your inverse measure.
Right click on your inverse measure inside the Marks card, hover over ‘Quick Table Calculation’, and select ‘Difference’. Your Gantt Bars should now be sized according to the Table Calculation and you should have a waterfall chart displaying the change of your measure across your dimension.
Alternative Step 5: Apply the ‘Running Total’ Table Calculation to your measure.
If you applied the Difference Table Calculation but want to show the Running Total of your measure instead, first remove your current Table Calculation. Do this by right clicking on the inverse measure, which currently has a Table Calculation (indicated by a triangle beside the measure), and then clicking ‘Clear Table Calculation’. Afterwards, right click your measure in the Rows shelf (not the inverse measure), hover over ‘Quick Table Calculation’, and this time select ‘Running Total’.
Step 6: Add a colour scale to the waterfall chart.
I used a discrete colour scale. To do this, create a new Calculated Field containing an IF statement that separates positive and negative changes.
Tip: You can drag your measure from the Marks card and drop it into the Calculated Field window to avoid typing the Table Calculation formula.
After creating this Calculated Field, right click it and select ‘Convert to Discrete’. Then drag and drop your new Calculated Field onto the ‘Colour’ icon in the Marks card. To change colours from the default, click the Colour icon, select ‘Edit Colours’.
If you want to have a continuous colour scale, simply hold down CTRL and drag your inverse measure inside the Marks Card onto ‘Colour’.
Optional: Hide first column.
If you applied the Difference Table Calculation, which by default calculates the difference between every value and the one before it, the first column value is always 0. Because of this, you may want to hide the first column when using a date dimension. You can do this by first right clicking your date field on the Columns shelf and selecting the ‘Discrete’ option. Now you can right click the first column label on the X-axis and select ‘Hide’.
If you followed along these steps, hopefully you have a nice looking waterfall chart in front of you.
