How to Make a Pie Chart in Looker

A pie chart is one of the most recognizable ways to visualize data, turning rows of numbers into a simple, digestible graphic. If you need to show how individual parts make up a whole, it’s a great choice. This guide will walk you through exactly how to create and customize a pie chart in Looker Studio, along with some powerful tips on when to use them - and when a different chart might tell a better story.

First Things First: Looker vs. Looker Studio

Before we go any further, let's clear up a common point of confusion. You've likely heard of both Looker and Looker Studio. While they sound similar, they are two different products:

Looker Studio (formerly Google Data Studio) is a free data visualization tool that lets you create reports and dashboards from various data sources. It's incredibly accessible and popular among marketers, agencies, and small businesses.
Looker is a more advanced, enterprise-level business intelligence platform that is part of Google Cloud. It's designed for deep data modeling and governance within large organizations.

This tutorial is for Looker Studio, the free, user-friendly tool perfect for creating marketing dashboards and business reports.

What Are Pie Charts Actually Good For?

A pie chart’s job is simple: to show composition or proportion. Think of it as slicing a pizza. Each slice represents a category, and the size of the slice shows its percentage of the total pizza. The entire pie chart must always add up to 100%.

Here are a few perfect use cases for a pie chart:

Traffic Sources by Device: Showing the percentage of website visitors from Desktop, Mobile, and Tablet.
Sales by Product Category: Breaking down total revenue by categories like "Apparel," "Accessories," and "Footwear."
Survey Responses: Visualizing the results of a multiple-choice question, like "How did you hear about us?"
Budget Allocation: Displaying how a marketing budget is split across channels like "Paid Search," "Social Media," and "Content Marketing."

The key takeaway is that pie charts work best when you have a handful of categories that clearly form a complete whole.

Connecting Your Data to Looker Studio

You can't build a chart without data. The first step in any Looker Studio project is connecting your data source. The good news is, it's a straightforward process.

If you're starting from scratch:

Go to lookerstudio.google.com and click on Blank Report.
Looker Studio will immediately prompt you to add data to the report.
You can choose from dozens of "Google Connectors" like Google Analytics, Google Sheets, and Google Ads, or explore partner connectors for other platforms.
For this example, let's assume you've connected to a Google Analytics 4 property, which is one of the most common use cases.

Once your data source is connected, you're ready to start building.

A Step-by-Step Guide to Creating a Pie Chart in Looker Studio

With your data source connected and a blank report canvas in front of you, building the actual chart takes just a few clicks.

1. Add a Chart to Your Report

In the Looker Studio toolbar at the top of the screen, click Add a chart. A dropdown menu will appear with a variety of chart types. Find the Pie chart option and select it. You'll see options for a standard "Pie chart" and a "Donut chart" - they are functionally the same, and you can switch between them later.

2. Place the Chart on the Canvas

Your cursor will turn into a crosshair icon. Click and drag on the report canvas to draw a box where you want your pie chart to appear. When you release the mouse, Looker Studio will generate a pie chart with some default data.

3. Configure Your Dimensions and Metrics

This is the most important step. On the right side of your screen, you'll see the Chart Panel. This is where you tell Looker Studio what data to show. For a pie chart, you need two things:

Dimension: This is the category you are measuring, or the "slices" of your pie. It's the "what."
Metric: This is the numerical value that determines the size of each slice. It's the "how much."

Let's use a common example: creating a chart of website users by device.

Under the Setup tab in the Chart Panel, find the Dimension field. Click on the default dimension and search for “Device category.”
Next, find the Metric field. Click on it and search for “Total users” or a similar user metric like “Sessions.”

As soon as you select your dimension and metric, the pie chart on your canvas will update instantly to show the percentage of users coming from Desktop, Mobile, and Tablet. It's that easy!

Customizing Your Pie Chart for Maximum Clarity

A default pie chart is good, but a well-styled one is great. You can customize nearly every aspect of your chart's appearance using the Style tab in the Chart Panel.

Slice and Color Control

Your chart will automatically assign colors, but you can change them to match your brand or to make data stand out. In the Style tab, you’ll find color selectors for each slice of your pie. You can also change the number of slices shown. If you have many small categories, Looker Studio allows you to group them automatically into an "Others" slice, which cleans up the chart significantly.

Changing to a Donut Chart

Many data visualization experts prefer donut charts over pie charts because they are slightly easier to read. The center hole reduces the emphasis on angles and encourages readers to compare the arc lengths of the slices, which the human eye is better at. To make this change:

Go to the Style tab.
Find the Slices section.
Adjust the Slice slider to create a hole in the center. The higher the number, the larger the hole.

Improving Readability with Labels

How the data is labeled makes a huge difference. Under the Labels section in the Style tab, you can customize:

Label Content: You can choose to show the Percentage, the Value, the Category Name, or a combination. Showing the Percentage is almost always a good idea.
Label Font: Adjust the font size, color, and family to fit the style of your dashboard.
Label Position: You can place the labels inside the slices or outside, optimizing for cleanliness and ensuring they don't overlap.

Common Pie Chart Pitfalls (and How to Avoid Them)

Pie charts are useful, but they are also one of the most misused charts in business reporting. Here are some common mistakes to watch out for.

Mistake 1: Too Many Slices

Have you ever seen a pie chart with 10 or more slices, each a tiny sliver with a label pointing to it? It's impossible to read. The brain isn't wired to compare the angles of so many small segments accurately.

The Fix: Limit your pie chart to a maximum of 5-6 categories. If you have more, group the smallest ones into a single "Other" slice or, even better, use a bar chart instead. A bar chart makes it much easier to compare the precise values of many categories.

Mistake 2: Using a Pie Chart to Show Change Over Time

A pie chart shows a snapshot of data from a single point in time (e.g., traffic sources for last month). It cannot effectively show trends.

The Fix: If you want to show how your mobile traffic has grown over the last six months, a line chart is the correct choice. Each data point on the line will represent a month, and the line itself will clearly visualize the trend up or down.

Mistake 3: Comparing Multiple Pie Charts

Placing two pie charts side-by-side to compare, say, market share from this year vs. last year is a classic reporting blunder. It's very difficult for a reader to compare the slice sizes between two separate circles.

The Fix: A grouped bar chart or a stacked bar chart is superior for this task. It places the categories on a common baseline, making direct comparison simple and intuitive.

Final Thoughts

You can now confidently create, customize, and deploy clear, effective pie charts in Looker Studio. Remember to use them for their intended purpose - showing parts of a whole - and to keep them simple and readable by avoiding common pitfalls like using too many categories.

While Looker Studio is great for building visuals, the process of knowing which dimensions and metrics to combine, cleaning up the styling, and getting everything just right is still a manual process. At Graphed, we created a tool that skips the manual drag-and-drop entirely. You can simply ask a question like, "Show me a pie chart of our Shopify revenue by product category for last quarter," and our AI-powered analyst builds the chart for you in seconds, pulling from your live data sources.