How to Create and Understand Heat Maps

What is a Heat Map?

A heat map uses color intensity to show values. Dark = High, Light = Low.

When to Use Heat Maps

Best for:

• Comparing many categories
• Finding patterns
• Showing intensity
• Time-based patterns

Creating a Heat Map

Step-by-Step

1. Drag a Dimension to Rows
2. Drag another Dimension to Columns
3. Drag a Measure to Color
4. Select "Square" from Marks dropdown
5. Done!

Example: Sales by Category and Month

1. Rows: Category
2. Columns: Month
3. Color: SUM(Sales)

Heat Map Structure

Jan Feb Mar Apr Furniture ■■■ ■■ ■■■■ ■■ Office ■■ ■■■■ ■■ ■■■ Tech ■■■■ ■■ ■■■ ■■■■ (Darker = Higher Sales)

Color Options

Default Colors

• Blue gradient (light to dark)
• Orange-Blue diverging

Custom Colors

1. Click Color on Marks card
2. Click "Edit Colors"
3. Choose a palette

Diverging Colors

Good for showing positive/negative:

• Red = Negative
• White = Zero
• Green = Positive

Reading Heat Maps

1. Look for patterns - Rows or columns that stand out
2. Find hotspots - Darkest colors
3. Spot trends - Color changes over time
4. Compare categories - Side by side

Adding Details

Add Labels

1. Drag measure to Label
2. Numbers appear in squares

Add Size

1. Drag measure to Size
2. Bigger squares = Higher values

Heat Map vs Highlight Table

Tips

• Use sequential colors for single measure
• Use diverging colors for +/- values
• Don't use too many categories
• Add labels if exact numbers matter

Summary

Heat maps show patterns with color intensity. Put dimensions on rows/columns, add color for your measure. Great for spotting trends!