Sankey Diagram in Power BI: Visualize Data Flows Easily

If you’re looking for a compelling way to visualize data movement or relationships between categories, the Sankey diagram in Power BI is a fantastic tool. Often overlooked, this powerful custom visual can illustrate data distribution and flow in a way that’s intuitive and easy to understand.

In this guide, you’ll learn how to:

• Install and use the Sankey diagram in Power BI
• Transform your dataset to fit the Sankey format
• Add multiple flow layers (e.g., year → priority → status)
• Customize your diagram for deeper insights

Let’s dive in and bring your data to life with flow visualizations.

What is a Sankey Diagram?

A Sankey diagram is a type of flowchart that visually represents how data moves from one category (source) to another (destination). The width of each flow represents the volume or weight of data, making it easy to see major contributors and bottlenecks at a glance.

For example, a company’s support ticket data can be visualized by year, department, and ticket status—clearly showing how volumes shift over time or across categories.

Step 1: Prepare Your Data in Power BI

Let’s start with a typical support ticket dataset that includes:

• Created Date
• Ticket Priority
• Ticket Status
• Department

This flat data structure is great for bar charts or tables, but not ideal for a Sankey diagram, which requires data in a source-destination-weight format.

Step 2: Add the Sankey Diagram to Power BI

The Sankey diagram is a custom visual, not included by default. To add it:

1. Go to the Visualizations pane in Power BI Desktop.
2. Click the ellipsis (⋯) → Get more visuals.
3. Search for “Sankey” and import it from AppSource.
4. You’ll now see the Sankey diagram icon in your visualizations panel.

Step 3: Create a Source-Destination Table

To build the Sankey diagram, you need a table that includes:

• Source (e.g., Year)
• Destination (e.g., Priority)
• Weight (e.g., Count of Tickets)

Use DAX to create a new table:

SankeyData = 
SUMMARIZE(
    Tickets,
    Tickets[CreatedYear],
    Tickets[Priority],
    "Count", COUNT(Tickets[TicketID])
)

This generates a simple source-destination-weight table.

Step 4: Build the Sankey Visual

1. Create a new page in Power BI.
2. Add the Sankey visual.
3. Drag in:
   • CreatedYear → Source
   • Priority → Destination
   • Count → Weight

You’ll now see the flow of tickets from year to priority level visualized as

Sankey paths.

 

Step 5: Add More Layers with UNION

To visualize flows across multiple dimensions (e.g., Year → Priority → Status), use multiple SUMMARIZE functions and combine them with UNION:

SankeyData = 
UNION(
    SUMMARIZE(Tickets, Tickets[CreatedYear], Tickets[Priority], "Count", COUNT(Tickets[TicketID])),
    SUMMARIZE(Tickets, Tickets[Priority], Tickets[Status], "Count", COUNT(Tickets[TicketID]))
)

Each additional flow layer adds depth and insight to your visualization.

Step 6: Explore and Analyze

With your Sankey diagram in place, you can:

• Click on a category to highlight specific flows
• Analyze bottlenecks or high-volume transitions
• Add tooltips or filters to enrich the analysis

The Sankey visual supports interactivity, making it great for dashboard use or exploratory data analysis.

Why Use Sankey Diagrams in Power BI?

• Visual clarity: Track how values flow across multiple categories.
• Data storytelling: Ideal for illustrating processes, funnels, or workflows.
• Interactive analysis: Filter and highlight segments for root-cause investigation.

Despite its power, the Sankey diagram in Power BI is underused—mainly because many users don’t know how to format their data correctly. With this guide, you can confidently add it to your visualization toolbox.

Learn More About Advanced Power BI Visualizations

Want to explore more custom visuals and advanced techniques? Check out the Advanced Power BI Boot Camp, where you’ll learn best practices for data modeling, visual storytelling, DAX, and automation.