Using Map Charts for Data Visualization and Insights

Data Visualization with Map Charts

A map chart is a data visualization that displays information using a geographic map as the backdrop. By coloring regions, placing markers, or layering spatial data on top of a map, you can uncover patterns, compare performance across locations, and tell a clear geographical story.

Map charts can represent both geographical data (countries, states, regions) and non-geographical data, such as manufacturing wafer maps or schematic layouts. They are powerful tools for spatial analysis, helping you understand distribution, proximity, and regional variation at a glance.

What Is a Map Chart?

A map chart uses a combination of geographical context and visual encoding to help users understand how values vary across locations. It typically includes:

• A base map layer showing a country, region, or custom shape
• Feature layers for shaded regions such as states or counties
• Marker layers that place points at specific coordinates
• Color encoding to represent values, such as density or performance
• Size or shape encoding for markers that represent magnitude

Map charts automatically update as your underlying data changes, making them ideal for real-time dashboards.

When Should You Use a Map Chart?

Use a map chart when the location, region, or spatial pattern is the key part of the story.

Map charts are excellent for showing:

1. Variation across regions

Examples: revenue by state, adoption trends by country, defect patterns on a wafer map.

2. Proximity or clustering

Examples: customer locations near a store, high-incident areas around a service center, drilling sites near a rig.

3. Density and intensity

Examples: patient populations by ZIP code, network outages, shipment volume per region.

4. Regional performance comparisons

Examples: field sales performance, election results, production output, fraud hotspots.

If the geographical context is irrelevant to your insight, a bar chart or line chart may communicate the information more clearly.

How a Map Can Answer Business Questions

A map chart will allow you to visualize data distribution across a region in a clear and easy-to-interpret manner. With data shown geographically, you can easily spot top-performing areas and compare them to the lowest performers. You will also be able to spot trends and identify outliers intuitively. 

Use a map chart to answer questions like, “Where is our new growth coming from?”. By calculating each region of global sales and its percentage increase over the past year, you will be able to use a map chart with shaded distribution to identify the fastest-growing areas quickly.

Maps can also help answer questions such as, “Are manufacturing plants following safety precautions?”. You can chart the number of accidents reported at each plant and quickly identify any outliers of plants with high accident rates. Add deeper insight into the data with a pie chart showing clustered information. You can compare accidents, safety write-ups, and OSHA violations for each location. The map can help indicate to your team whether or not more training on safety processes is needed.

Types of Map Charts

Different map types help communicate different kinds of insights.

Filled Maps (Choropleth Maps)

Shaded regions represent values such as revenue, temperature, or population.

Marker Maps

Points placed at exact locations, useful for store locations, event points, or asset tracking.

Bubble Maps

Markers scaled by a numeric value, ideal for showing concentration or intensity.

Heat Maps

Color gradients show high- and low-density regions.

Pie Chart Maps

Mini pie charts placed on locations to show categorical proportions.

Bubble Pie Maps

Combines bubble sizing and pie segmentation to show multiple values at once.

Non-Geographical Maps

Useful for manufacturing, hardware layouts, floor plans, or defect analysis (wafer maps).

How Map Charts Work

A map chart visually encodes your data through a combination of layers and visual cues.

Layers

• Base map – countries, states, or custom shapes
• Feature layers – regions that can be filled or shaded
• Marker layers – points representing specific locations
• Image layers – optional diagrams or custom layouts

Visual Encoding

• Color – gradients or categories indicate performance or values
• Size – marker size reflects magnitude (e.g., sales volume)
• Shape – different shapes for categories or statuses
• Tooltips – provide details on hover
• Dynamic updates – map refreshes as new data comes in

Interactions

Modern map charts include:

• Zoom and pan
• Search
• Region selection
• Drill-down filters
• Hover tooltips
  These interactions help users explore data at multiple levels.

Common Business Scenarios for Using a Map

You can use maps to help inform business decisions for a wide range of use cases across departments, including:

Sales & Marketing

• Compare sales across territories
• Visualize customer density
• Identify underperforming regions

Operations & Supply Chain

• Monitor warehouse coverage
• Track delivery routes and bottlenecks
• View asset locations or service zones

Finance

• Compare branch profitability
• Identify regional cost variations
• Monitor fraud hotspots

IT & Security

• Visualize system outages by region
• Plot device locations
• Identify incident clusters

Healthcare

• Track patient or clinician distribution
• Analyze utilization across facilities

Manufacturing

• Use wafer maps to visualize defects
• Map equipment performance or downtime

Map charts help teams quickly spot patterns that would be hidden in spreadsheets or tables.

Using a Map in a Dashboard

While maps are great at showing geographic distribution of your data, they can’t always make it easy to compare parts of your data to a whole or show trends. Consider pairing a map with other chart types on your dashboard to convey additional data information. 

Combine maps with:

• Bar charts (compare categories within a region)
• Line charts (show trends over time)
• Bubble charts (highlight outliers or high-value locations)
• Forecasting charts (predict changes across regions)

For example:
A map chart might show regional sales performance, while a bar chart breaks down the top-performing products in each area.

This combination creates a complete, multi-dimensional story.

Best practices for using a map chart

1. Clean your data first

Standardize region names (e.g., “CA” vs “California”) to avoid incorrect mapping.

2. Label effectively

Add tooltips or labels to highlight important values.

3. Use clear visual cues

Use color gradients consistently. Avoid too many shades, which can confuse readers.

4. Keep maps uncluttered

Limit the number of markers or layers so users can focus on what matters most.

5. Use colorblind-friendly palettes

Helps ensure accessibility for all users.

6. Be mindful of map distortions

Geographical projections distort area sizes — avoid comparing areas visually based on size alone.

7. Pick the right level of detail

Country-level maps are great for broad trends. ZIP-code or county-level maps work best for hyperlocalized analysis.

8. Combine maps with other chart types when needed

If geography isn’t essential to your insight, another chart may communicate your message more clearly.

Maps are a great data visualization tool to add to reports and dashboards. Use them to help readers understand the geographical impact of your datasets. To learn more about other charts and data visualization techniques, talk to a Domo expert today.