Creating Pie Charts in Tableau

How to Create a Pie Chart in Tableau

Pie charts in Tableau are useful for visualizing proportions of a whole and are typically used when dealing with categorical data.

Steps to Create a Pie Chart

1. Open Tableau and connect to your dataset.
2. Drag a dimension (e.g., Category) to the Columns shelf.
3. Drag a measure (e.g., Sales) to the Rows shelf.
4. Change the Mark type to Pie in the Marks card.
5. Drag the same measure (Sales) onto Angle to determine the slice proportions.
6. Drag the dimension (Category) onto Color to differentiate the segments.
7. Adjust Labels by dragging the dimension to the Label card.

How to Make a Pie Chart Bigger in Tableau

By default, Tableau pie charts may appear small. To increase their size:

1. Click on the pie chart to select it.
2. Open the Size Card in the Marks pane.
3. Drag the Size slider to increase the chart’s size.
4. If in a Dashboard, ensure the pie chart is using the entire view to make full use of the available space.

Best Practices for Pie Charts in Tableau

• Use sparingly – Pie charts are best for showing 2-5 categories; more than that can be hard to interpret.
• Sort slices – Ordering segments from largest to smallest improves readability.
• Consider Alternatives – A bar chart or donut chart may be more effective for comparisons.

Comparing Pie Charts in Tableau to SQL-Based Reporting in Evidence

In Evidence, all chart transformations occur at the query level before visualization. Instead of relying on Tableau’s visual controls, you can write SQL queries to structure data before rendering.

Example: Creating a Pie Chart in Evidence

In Evidence, you can create a pie chart using the ECharts component.

```sql pie_query
select 'Apple' as pie, 60 as count
union all
select 'Blueberry' as pie, 70 as count
union all
select 'Cherry' as pie, 40 as count
union all
select 'Pecan' as pie, 35 as count
```

```sql pie_data
select pie as name, count as value
from ${pie_query}
```

<ECharts config={
    {
        tooltip: {
            formatter: '{b}: {c} ({d}%)'
        },
        series: [
        {
          type: 'pie',
          data: [...pie_data],
        }
      ]
      }
    }
/>

This ensures that data aggregation is handled at the SQL level, reducing dependency on in-tool calculations.

Tableau vs Evidence Pie Charts

Tableau provides an intuitive way to create pie charts with flexible size adjustments through the Size Card. However, for structured, SQL-driven reporting, Evidence offers a query-first approach with precise control over data preparation.