Tableau Course
Maps in Tableau
Tableau has built-in geographic intelligence — it recognises country, state, city, and postcode fields automatically and plots them on an interactive map without any external data files. Maps reveal spatial patterns that tables and bar charts cannot: which regions outperform, where customers cluster, and how geography shapes your business.
Geographic Roles — How Tableau Recognises Location Data
When Tableau detects a field that looks like a geographic entity — a state name, a country, a city, a postcode — it assigns it a Geographic Role automatically. The field appears in the Data pane with a small globe icon instead of the usual dimension icon. This geographic role tells Tableau which latitude and longitude coordinates to use when plotting the field on a map.
| Geographic Role | Example Values | Tableau Plots As |
|---|---|---|
| Country / Region | United States, Germany, Japan | Filled polygon or centroid point |
| State / Province | California, Texas, Ontario | Filled polygon or centroid point |
| City | New York, Chicago, London | Point at city centroid |
| ZIP Code / Postcode | 10001, SW1A 1AA | Point at postcode centroid |
| Latitude / Longitude | 40.7128, -74.0060 | Exact coordinate point |
If a field is not recognised automatically, right-click it in the Data pane → Geographic Role and assign the correct role manually. A field named "State_Code" containing two-letter US state abbreviations may need manual assignment if Tableau does not detect it automatically.
Filled Maps — Colour by Region
A filled map colours the entire polygon of each geographic area — each state, country, or region is shaded according to a Measure. This is the clearest map type for showing regional performance at a glance, because the large coloured areas are easy to compare visually.
Filled Map — Labelled Mockup
Symbol Maps — Sized Circles at Each Location
A symbol map keeps the mark type as Circle (the default when you double-click a geographic field) and encodes a Measure through the Size channel — larger circles mean larger values. Symbol maps are better than filled maps when you want to show the magnitude of a Measure at each location without implying that the entire geographic area has that value. They are also the right choice when your data is at city or postcode level — filled map polygons at that resolution are too small to read.
Symbol Map — Labelled Mockup
Map Formatting and Background Options
Go to Map menu → Map Layers to control which background elements appear — coastlines, country borders, state borders, roads, and land cover. For a clean dashboard presentation, turn off everything except Land and Country/Region Borders. For exploratory analysis at city level, turn on Streets and Highways.
Go to Map menu → Background Maps to switch the base map style between Normal, Dark, Light, Streets, Outdoors, and Satellite. The Light style works best for filled maps because the pale background lets the colour encoding stand out. The Dark style works well for symbol maps because bright circle colours pop against a dark background.
Fixing Unrecognised Locations
When Tableau cannot match a location value to its internal database, it marks it as an unknown location — shown by a small indicator in the bottom-right corner of the map view. Click the indicator to open the Edit Locations dialog. Here you can manually match unrecognised values (such as abbreviated state names or non-standard city spellings) to Tableau's known geographic entities, or enter custom latitude and longitude coordinates.
The most powerful map in a business context is the symbol map with Size = Revenue and Color = Profit Ratio — the same killer combination as the treemap, but now laid out geographically. A large orange circle means a high-revenue city that is losing money. That city needs immediate attention. A cluster of small blue circles in one region means lots of small, profitable transactions — a different story and a different action. Maps also reveal something that charts never can: distance and clustering. If all your loss-making cities are concentrated in one geographic corridor, that is a supply chain or pricing problem tied to geography — invisible in any other chart type. Always check your unknown locations indicator after building a map. Even one unrecognised location means a data point is missing from the view, and in a regional sales analysis that missing point could be your most important city.
Practice Questions
1. After double-clicking the State field, Tableau shows a symbol map with one dot per state. What single change converts it to a filled map where entire state shapes are coloured?
2. After building a map, an indicator appears in the bottom-right corner showing some locations are unrecognised. How do you fix these?
3. You want a city-level map where circle size shows total Sales and circle colour shows whether each city is profitable or loss-making. Which map type and channel configuration achieves this?
Quiz
1. A field named "State_Code" containing two-letter US state abbreviations is not recognised automatically as a geographic field. How do you fix this?
2. Your data is at postcode level and you want to show both Sales magnitude and Profit performance per postcode on a map. Which map type is most appropriate?
3. A filled map's colour encoding is hard to see against the default map background. Where do you go to change the background map style?
Next up — Lesson 29: Density maps — using heat-based colour intensity to reveal where data points concentrate across a geographic area.