What is a Filled Map in Tableau?

A filled map in Tableau turns your geographic data into a powerful, color-coded visual story, instantly revealing regional trends and patterns. If you need to show how a metric like sales, population, or customer count varies across states, countries, or sales territories, the filled map is your best friend. This article will walk you through what a filled map is, why you should use it, and exactly how to build one step-by-step.

So, What Exactly is a Filled Map in Tableau?

Think of a regular map. Now, imagine coloring in each state or country based on a specific data point. That’s a filled map. In technical terms, it's a type of data visualization where geographical areas (called polygons) are shaded in proportion to a related measure. The darker the shade of blue in a state, for example, the higher the sales.

This is different from a symbol map, which places dots or other shapes on specific locations, like cities or store addresses. While symbol maps are great for showing individual data points, filled maps are designed to show data aggregated over an entire defined area, like a county, state, or postal code.

Tableau makes this possible by recognizing geographical data types. When you load data containing fields like "Country," "State," or "City," Tableau automatically assigns them a "geographic role." This tells the software how to plot your data correctly on a map background, allowing you to create rich, informative visuals with just a few clicks.

Why Use a Filled Map? The Key Benefits

While a table of sales numbers for all 50 states is accurate, it's not very insightful. The human brain processes visual information far more quickly than text-heavy spreadsheets. Filled maps turn that boring table into a canvas of immediate insight.

• Instantly Spot Geographic Patterns: You can see at a glance if your best-performing regions are clustered on the West Coast or if there are surprising pockets of activity in the Midwest. This kind of high-level overview is nearly impossible to get from a spreadsheet.
• Compare Regional Performance Easily: Need to compare sales in the Northeast versus the Southeast? A filled map makes these comparisons intuitive. The color gradients instantly show you where performance is strong, weak, or average, without needing to sort or filter a table.
• Make Data More Engaging: When presenting to stakeholders, a colored map is far more compelling and easier to understand than dense tables. It tells a clear story that gets your point across quickly and memorably, making you look like a data visualization pro.
• Identify Gaps and Opportunities: By visualizing data like customer distribution or lead volumes, you can quickly identify underserved areas or new market opportunities. A map might reveal a state with high web traffic but low conversions, signaling a target for a new marketing campaign.

Before You Begin: Preparing Your Data for Mapping

The magic of Tableau maps starts with well-structured data. Before you jump into building your viz, taking a moment to check your data source will save you a lot of headaches later. At its core, you need two fundamental things:

1. A column containing your location names (e.g., states, countries, postal codes).
2. A column containing the numerical data (or "measure") you want to visualize (e.g., Sales, Profit, Headcount).

Here’s a simple example of how your data might look in a spreadsheet:

State,Sales,Region California,75000,West Texas,62000,South New York,58000,East Florida,45000,South Illinois,39000,Midwest

The Importance of Geographic Roles

Tableau is smart, but it needs a little help. Its ability to create maps hinges on correctly identifying which of your data columns contains geographic information. This is called a "Geographic Role."

Supported roles include a wide range of types:

• Country / Region
• State / Province
• County
• City
• ZIP Code / Postcode
• Area Code

When you connect your data, Tableau will try to automatically detect and assign these roles based on your column headers. If it gets it wrong, you can manually set it, which we'll cover in the next section.

Watch out for ambiguous data! If your data just says "Georgia," does that mean the U.S. state or the country in Eurasia? You may have to clean your data or tell Tableau which one to use to avoid errors.

A Step-by-Step Guide to Creating a Filled Map in Tableau

Alright, let's build your filled map. We’ll use a simple example of visualizing sales by state in the United States.

Step 1: Connect to Your Data Source

First, open Tableau and connect to your data file (e.g., an Excel spreadsheet, CSV file, or a server-based data source). Once loaded, your columns will appear in the "Data" pane on the left side of the screen.

Step 2: Check and Assign Geographic Roles

In the Data pane, look for your location field (e.g., "State"). You should see a small globe icon next to it. This indicates Tableau has correctly identified it as geographic data.

If you don't see a globe icon, right-click on the field, hover over Geographic Role, and select the correct role (e.g., a "City" field might mistakenly be read as text).

Step 3: Build the Basic Map View

Simply double-click your geographic field ("State"). Tableau will automatically add the longitude and latitude to the Columns and Rows shelves and place dots on your map, one for each state in your data. Don't worry, we're about to turn these dots into shaded regions.

Step 4: Change the Mark Type to "Map"

Look for the "Marks" card, which is typically to the left of your visualization. It controls how your data is displayed. Click the dropdown menu that likely says "Automatic" and select "Map".

Instantly, your dots will transform into shaded areas - congratulations, you've created a filled map!

Step 5: Add Color with Your Measure

Your map is just a solid color right now. Let's make it meaningful. Find the measure you want to visualize (e.g., "Sales") in the Data pane and drag it onto the "Color" box on the Marks card.

Tableau will automatically color each state based on its sales total, typically a gradient where lighter shades represent lower values and darker shades represent higher values. A color legend will appear on the right to explain the scale.

Step 6: Customize and Refine Your Map

Now for the fun part! You can customize your map to make it even more clear and informative.

• Edit Colors: Click on "Color" on the Marks card, then select "Edit Colors..." to switch palettes. A "Red-Green Diverging" palette is great for showing profit (positive and negative), while a simple "Blue" or "Orange" sequential palette is perfect for totals like sales or population.
• Improve Tooltips: A tooltip is the little box of information that pops up when you hover over a state. Drag other relevant fields (like "Profit" or "Region") onto the "Tooltip" box on the Marks Card to add more context without cluttering the map.
• Add Labels: Want to see the sales number directly on the state? Drag your "Sales" measure onto the "Label" box on the Marks card. You can also drag the "State" field to "Label" to display the state names.

Common Pitfalls and Troubleshooting Tips

Sometimes things don't go perfectly on the first try. Here are a couple of common issues and how to fix them quickly.

• Seeing an "Unknown Locations" Warning: If you see a small gray indicator in the bottom-right corner of your map that says something like "49 unknown," it means Tableau can't recognize some of your location names. This is often due to misspellings ("Califorina") or non-standard abbreviations ("USA" instead of "United States"). Click the indicator and choose "Edit Locations..." to manually match your unrecognized spellings to Tableau's known locations.
• Your data still shows up as dots (or another shape): The most common reason is that the Mark Type is not set correctly. Double-check that the dropdown menu on the Marks card is set to "Map," not "Automatic" or "Shape."
• Map looks patchy or some areas are blank: This usually means you have "null" or missing data for those specific locations in your spreadsheet. They exist on the map, but because there's no data value associated with them, Tableau can't color them in.

Final Thoughts

Building a filled map in Tableau is an intuitive way to transform geographic data into real business insights. By coloring areas based on key metrics, you can quickly analyze regional performance, spot trends, and communicate your findings in a visually compelling way that a spreadsheet just can't match.

While mastering Tableau is an excellent skill, we believe getting insights from your data shouldn't be a time-consuming technical exercise. That's why we created Graphed. Instead of manually assigning roles, dragging fields, and adjusting menus, you can simply ask a question in plain English, like "Show a map of sales by state," and get a live, interactive dashboard instantly. It’s like having a data analyst on your team who works in seconds, not hours.