Waterfall charts are a great way to visualize how different factors make up the final result. Whether it’s tracking revenue, breaking down costs, or analysing a business’s cash flow.. Unlike a bar chart, waterfall charts show positive and negative changes, making it easy to see what is driving your numbers up or down.
In this blog, we’ll cover how to build a waterfall chart in Sigma Computing. We’ll use our trusted sample superstore data to examine the store’s revenue so that you can follow along. We’ll also examine formatting options Sigma provides and the best practices to use when creating waterfall charts in Sigma.
What Are Waterfall Charts?
A waterfall chart is a bar chart that visually represents how an initial value is influenced by positive and negative changes over time. Waterfall charts show incremental changes rather than just totals. Each bar shows a change with positive values adding up and negative values bringing the total down. Let’s get started!
How to Create a Waterfall Chart in Sigma Computing
Prepping the data
Start by downloading the superstore dataset if you don’t already have it. While uploading the file into Sigma, note that Sigma doesn’t parse .csv files with multiple sheets/tabs, so save each of the tabs as separate .csv files. To build our waterfall chart, we’ll be using the Orders and Returns tables from the superstore data.
Step 1 – Connect to the data in Sigma.
Now, let’s connect our files to Sigma. To do this, open Sigma in the browser. Click on Create New button on the top left corner of the page, then click on Workbook.
To upload our .csv files we created, select Data, then Table,and click on CSV to get the tables in Sigma.
Step 2 – Consolidate Order and returns data into one table.
Now, we’ll have two tables in Sigma. The orders table has details of all the sales made, but doesn’t have any information about the returns. So, let’s do a left join on the orders table to see the return details as well. To do this, click on the Data icon to create a Table, this time with Join.
Select the Orders and Returns tables. Set the Join type to Left Join and the keys to join on as Order ID. Click on Preview Output, then Done. Rename the table to Superstore. Now that we have one unified table, let’s create a few calculations in the next section.
Step 3 – Create calculations for profit, sales, etc.
Let’s build some calculations: Sales, Discounts, and Returns.
Sales = Sum([Sales])
Since we have percentages of discounts on the order, we can calculate the discount amount.
Discounts = -Sum([Sales] * [Discount])
This calculates the total returns by summing up the Sales values only where Returned = ”Yes”.
Returns = -Sum(If([Returned] = "Yes", [Sales], 0))
The negative sign ensures that returns and discounts are treated as deductions.
Step 4 – Add fields to groupings.
To make the waterfall chart easy to view by year, month, or quarter, we’ll group the data by Order Date. First, create a new calculation and rename it to Order Period. Then create a Segmented control with Preset Date options. Add the order period calculation to the grouping section along with Sales, Discounts, and Returns.
Order Period = DateTrunc([Order-Period], [Order Date])
Step 5 – Create child tables for Sales, Discounts, and Returns.
We’ll now break the data into three child tables. Select the Superstore table. Click on the Bar chart icon in the top right corner of the table and select Table from the dropdown to create a child table.
Now that we have our child table, remove all the fields except Order Period and Sales. Then, create a second child table and keep only Order period, Discounts. Repeat the same for Returns, the last child table.
Step 6 – Combine all the tables using a union.
Now that we have separate child tables for Sales, Discounts, and Returns, the next step is to bring them back together. We’ll do this by using a union. This will give us a Single column for the order Period and another for all the positive and negative values, and allow us to create the waterfall chart. To create a union in Sigma, click on Data, then Table, now select Union.
Select all 3 tables and select the mapping of the columns like below. In the new table, rename the Sales column to Revenue and also rename the new table to Revenue.
Our data is now prepped to build the waterfall chart. Let’s look at the next steps to visualize and bring it to life in Sigma!
Building the Waterfall Chart
In this section, we’ll look at the steps to create the waterfall chart.
Step 1 – Add a chart child element.
To add a chart element in Sigma, click on the table Revenue, select the Bar Chart icon, and select Chart.
Step 2 – Select the Waterfall chart option.
The default chart type in Sigma is a bar chart. To change it, go to the Chart Type dropdown available under the Properties tab, select Waterfall.
Step 3 – Insert relevant fields.
Add the Order Period in the x-axis and Revenue in the y-axis. Uncheck the Aggregate Values checkbox.
This is the default chart that Sigma has generated.
Step 4 – Clean up the chart for readability.
Now that the waterfall chart is ready, let’s explore some formatting options in Sigma to make it clearer and easier to understand.
Start by formatting the Revenue column. Right-click on the column, go to Format, and choose to display values in SI Units. By default, Positive values are green, Negative values are red, and the starting/ending values are gray. To suit our preference we’ll change it by going to the Properties tab under the Color section, selecting the Total color to be blue.
Next let’s head over to the Format tab to improve the overall appearance.
Set the x-axis label to rotate by 0 degrees to make it horizontal under the x-axis section
Check the Data labels box under the Data Labels section
Check the Show Legend box to display the color legend and set the Position to Bottom under the Legend section
We’ll also change the End Value Label under the Waterfall Shape section to “Current Revenue”
Finally, we’ll add a dynamic title to reflect the order period selected by the user. We can do this by either clicking directly on the auto-generated Chart Title or navigating to the Format tab in Sigma. In Sigma, titles can be dynamic by just typing = followed by the field name. In our case, type =[Order-Period] to show the selected period as part of the chart title.
With those final touches our waterfall chart will end up looking something like this.
Best Practices for Waterfall Charts
Some of the best practices we can follow to ensure the waterfall chart is clear and concise.
Keep it simple: Limit the number of categories to highlight the most important drivers/factors. Too many categories can clutter the chart; group the smaller categories into an “Other” category to keep things readable.
Prep your data: Structure the data set properly before building the chart. Make sure additions and deductions are well defined so that the waterfall logic is easy to follow.
Add Tooltips for context: Use tooltips to give extra details like whether a deduction is due to returns or discounts, without overwhelming the visual.
Use Interactive Controls: Add filters, parameters, and dynamic titles to enhance user interactivity. This allows the user to explore the data from different angles and levels of detail.
Closing
And that’s a wrap! You’ve now got everything you need to create clear, insightful waterfall charts in Sigma. This blog covers everything from prepping the data to customizing the visuals. With these steps, you can start adding easy-to-understand waterfall charts to your dashboards.
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