How to Make a Pie Chart in Looker with AI

A pie chart is one of the simplest ways to show how different parts make up a whole. This quick guide will walk you through how to create a pie chart in Looker Studio (formerly Google Data Studio) using both the traditional method and the newer, faster AI-powered features. We’ll also cover some essential best practices to make sure your charts are clear, accurate, and easy to understand.

What a Pie Chart is and When to (Carefully) Use One

A pie chart, sometimes called a circle chart, displays data in a circular graph where individual "slices" represent a percentage or proportion of the total. Think of it as slicing up a pizza - each slice is a part of the whole pie. It’s a great tool for quickly showing compositional data.

For example, a pie chart is perfect for visualizing things like:

• Website traffic sources (Organic Search, Social, Direct, etc.)

• Sales distribution by product category (Clothing, Electronics, Home Goods)

• Market share between competitors in an industry

• Breakdown of a marketing budget by channel (paid search, social ads, content)

When You Should Avoid a Pie Chart

While pie charts are familiar, they have some important limitations. Using them in the wrong context can make your data confusing or even misleading. It’s best to choose a different chart type, like a bar chart or line graph, when you need to:

• Compare more than 5-7 categories: As you add more slices, the chart becomes a cluttered, unreadable rainbow. A bar chart is much cleaner for comparing many categories.

• Show values that are close together: It’s very difficult for the human eye to accurately compare the sizes of similarly-sized circular segments. A bar chart makes these subtle differences instantly obvious.

• Track changes over time: A pie chart represents a single point in time. If you want to show how traffic sources have changed month-over-month, a line chart is the clear winner.

Remember, the goal is clarity. A simple bar chart is often a more effective and honest way to present your data.

How to Make a Pie Chart in Looker Studio Manually

Before AI took over, creating a pie chart in Looker Studio involved clicking through menus and dragging fields into place. This method still works perfectly well and gives you full control over every aspect of your chart. Here’s how to do it step-by-step.

For this example, let's pretend we're visualizing website sessions by device from a Google Analytics data source.

Step 1: Get Your Data Ready

First, make sure your data source is connected to Looker Studio. If it's not already, go to Resource > Manage added data sources > Add A Data Source. Select your desired connector (like Google Analytics, Google Sheets, or BigQuery) and authorize the connection.

Step 2: Add a Chart to Your Report

Once you’re in your report canvas, go to the toolbar and click Add a chart. Look for the "Pie" section in the dropdown menu and select either the standard ‘Pie chart’ or a ‘Doughnut chart’.

Step 3: Configure Your Chart’s Data

After you place the chart on your canvas, the configuration panel will appear on the right side. This is where you tell Looker Studio what data to display.

• Dimension: This is the category you want to slice your pie by. It defines what each slice represents. For our example, drag the Device Category field from your available fields list and drop it into the ‘Dimension’ box.

• Metric: This is the numerical value that determines the size of each slice. It answers the "how much?" question. Drag the Sessions field into the ‘Metric’ box.

Looker will immediately generate a pie chart showing the proportion of sessions from desktop, mobile, and tablet users.

Step 4: Customize the Style

Right next to the 'Data' tab in the configuration panel, you'll find the 'Style' tab. Here, you can fine-tune the chart's appearance to make it more readable and visually appealing.

• Labels: You can add labels to show the percentage, the raw value, or the category name directly on the slices. This is often better than relying on a separate legend.

• Slice Colors: Customize the color of each slice to match your brand or to make specific categories stand out.

• Legend: Adjust the position and formatting of the chart's legend, or hide it completely if your labels make it redundant.

• Background and Border: Change the chart’s background color and add a border to help it stand apart from other elements on your dashboard.

Take a few moments to make these adjustments. A well-styled chart isn't just prettier, it's a lot easier to interpret at a glance.

How to Make a Pie Chart with Looker Studio’s AI Features

The manual process is straightforward, but what if you could do it even faster? Looker Studio now integrates Gemini’s AI capabilities, which let you generate charts and get suggestions by simply describing what you want in plain English. This completely changes the workflow, especially for those who are new to the platform or need to build reports quickly.

Create a Chart Using Natural Language

The "Create chart from prompt" feature lets you skip the menus and ask for what you need directly. Instead of selecting chart types and dragging dimensions, you just type a sentence.

First, find the Create chart from prompt ✨ icon in the Looker Studio toolbar and click it. A text box will appear.

Now, just type your request. Try to be clear and specify the chart type, the dimension, and the metric. For our device traffic example, you could write:

pie chart showing sessions by device category

Or for something a bit more complex from another data source:

as a pie chart, show me Shopify sales from the last quarter by product category

Looker Studio's AI will interpret your prompt, identify the correct fields, and generate the chart for you. It might take a moment to process, but a fully configured pie chart will appear on your canvas. From there, you can still click on it and head over to the ‘Data’ and ‘Style’ tabs to make any manual adjustments you need.

This approach significantly lowers the learning curve. You only need to know what you want to see, not exactly where to click to build it.

Best Practices for Clearer Pie Charts

Whether you create your pie chart manually or with AI, following a few design principles will ensure your message is communicated effectively. Badly designed charts can cause more confusion than clarity.

1. Keep Slices to a Minimum

A pie chart is most effective with just a few slices. A good rule of thumb is to have no more than five categories. If you have more, the chart gets crowded and hard to read. Group smaller, less important segments into a single "Other" category to keep your visualization clean.

2. Label Slices Directly

Forcing your audience to look back and forth between a legend and the pie chart itself adds unnecessary work. Instead, try to label each slice directly with both the category name and its percentage value. This makes the chart scannable and easier to digest.

3. Order for Readability

Don’t leave your slices in a random or alphabetical order. Arrange them logically to help readers compare segments. A common practice is to order slices from largest to smallest, starting at the 12 o'clock position and moving clockwise.

4. Use Colors Thoughtfully

Assign distinct, high-contrast colors to each slice so they are easy to tell apart. If you’re highlighting a specific category, use a bold, saturated color for that slice and more muted tones for the others. Always consider accessibility and check that your colors can be distinguished by those with color vision deficiencies.

5. Avoid 3D, Exploding Slices, and Other "Chart Junk"

3D effects distort the perspective of a pie chart, making slices in the foreground appear larger than those in the background, even if their values are smaller. This is visually misleading. Similarly, flashy effects like "exploding" slices rarely add real value and often just clutter the visual. Stick to a simple, flat design for maximum clarity.

Final Thoughts

Manually creating a pie chart in Looker Studio gives you precise control, while the new AI features offer a much faster path from data to visualization. By combining these methods with solid design principles, you can create reports that effectively communicate proportions and help your team make better decisions.

While Looker's built-in AI assistant is a great feature, we found that building complete, cross-platform dashboards still required a lot of manual work. That’s why we built Graphed to be a complete conversational analytics tool. Instead of just creating one chart, you can connect all your data sources - from Google Analytics and Facebook Ads to Shopify and HubSpot - and ask Graphed to build an entire interactive dashboard in seconds. You can ask follow-up questions, get live updates automatically, and receive AI-powered insights, all without ever touching a settings panel.