How to Create a Funnel Chart in Looker with AI

A funnel chart is one of the most powerful ways to visualize how users move through a process, whether it’s a marketing campaign, a sales pipeline, or a product onboarding flow. This article will walk you through exactly how to build a clear and effective funnel chart in Looker Studio (formerly Google Data Studio) and start spotting opportunities to improve your conversions.

What is a Funnel Chart, and Why is it So Useful?

Think of a funnel chart as a visual story of your customer's journey. It shows the number of people at each stage of a process, starting with a large group at the top and narrowing down at each subsequent step. The shape immediately highlights where you're losing people, so you can focus your attention on the biggest leaks.

For example, a typical marketing funnel might look like this:

• Stage 1: Website Visitors - All the people who landed on your site.

• Stage 2: Product Views - Visitors who looked at a specific product page.

• Stage 3: Added to Cart - The subset who added that product to their cart.

• Stage 4: Purchases - The final group who completed the checkout.

By visualizing this, you can instantly see the drop-off between each stage. If you have tons of visitors but very few product views, you might have a messaging problem on your homepage. If many people add items to their cart but don’t purchase, you should investigate your checkout process for friction.

Setting the Stage: Prepping Your Data in Looker Studio

Before you can build the chart, your data needs to be structured properly. The biggest challenge with funnel charts in Looker Studio is that your data source, like Google Analytics, doesn't typically provide perfect, pre-packaged "funnel stages." You need to define them yourself.

For a funnel chart, you need two things for each stage:

1. A name for the stage (e.g., "Sessions," "Add to Carts").

2. A count of users or events for that stage.

Looker Studio doesn’t have a native one-click "Funnel Chart" widget. But don't worry - we can build a visually identical (and more flexible) version using a bit of creative ingenuity and another chart type. The most reliable method is to create a 100% Stacked Bar Chart and format it to look and act just like a funnel.

Building Metrics for Your Funnel Stages with GA4 Data

Since we need a separate metric for each stage, we'll use calculated fields to count users or events based on specific conditions. This is the heart of the setup.

In your Looker Studio report, connect to your Google Analytics 4 data source. Then, go to Resource > Manage added data sources > Edit > Add a Field. We are going to create a metric for each step of our e-commerce funnel.

Here are example formulas you could use for each stage:

1. All Sessions

This is usually a default metric. You can simply use Sessions if it's available. If not, you can create it.

2. Product Viewers

We'll create a new field named "Viewed Product" that counts users who triggered the 'view_item' event.

COUNT(CASE WHEN Event name = "view_item" THEN User pseudo ID END)

3. Added to Cart

Create another field named "Added to Cart" for the 'add_to_cart' event.

COUNT(CASE WHEN Event name = "add_to_cart" THEN User pseudo ID END)

4. Began Checkout

Create a field named "Began Checkout" for the 'begin_checkout' event.

COUNT(CASE WHEN Event name = "begin_checkout" THEN User pseudo ID END)

5. Purchases

And finally, create "Purchases" for the 'purchase' event.

COUNT(CASE WHEN Event name = "purchase" THEN User pseudo ID END)

The logic here is pretty simple: The CASE WHEN statement tells Looker to only count a user if their action (the Event name) matches the stage we're defining. These calculated fields give us the distinct numbers we need for our funnel.

Step-by-Step: How to Build the Funnel Chart

With our custom metrics ready, it's time to build the visualization. It might seem unconventional at first, but this stacked bar chart method is incredibly powerful.

Step 1: Add a 100% Stacked Bar Chart

Click Add a chart from the toolbar and select the 100% Stacked Bar Chart. Place it on your report canvas.

Step 2: A Little Trick with the Dimension

Typically, a bar chart uses a dimension to break data into different bars (e.g., by Country or by campaign). For our funnel, we want a single, solid bar. To achieve this, we'll create a simple calculated field to act as a placeholder dimension.

• In the chart's Setup panel on the right, click on the current Dimension.

• Click Create Field.

• Name it "Marketing Funnel."

• In the formula box, simply type in "Sales Funnel" (including the quotes).

• Click Apply.

This trick forces all our metrics into one visual block instead of separate bars.

Step 3: Add Your Metrics in Order

This is where it all comes together. Underneath the Metric section of the setup panel, you need to add the calculated metrics you created earlier. It's crucial to place them in the correct funnel order, from the widest stage to the narrowest.

It should look like this:

1. Sessions

2. Viewed Product

3. Added to Cart

4. Began Checkout

5. Purchases

You’ll immediately see a colored bar appear, but it won’t look like much of a funnel yet. That’s next.

Step 4: Style Your Chart to Look Like a Funnel

Now, let's make it intuitive and easy to read. Click on the chart, then navigate to the Style tab in the right-hand panel.

• Bar Colors: Assign a distinct, sequential color for each metric. It often helps to use variations of the same color, from light to dark, to represent progression.

• Data Labels: Check the box for Show data labels. This will display the actual numbers directly on each segment of the bar, which is essential for a funnel. You can also select "Show as Number" and "Show Percentage."

• Legend: Set the legend to None to remove the clutter to the side of the chart. The data labels do the work for you.

• Axes: Under the X-axis options, check Show axis but uncheck Show axis title. For the Y-axis, uncheck Show axis altogether.

• Grid: Change the grid color to transparent to clean up the background.

And there you have it! You now have a clean, insightful funnel chart right on your Looker Studio dashboard.

Bonus: Interpreting Your Funnel and Taking Action

Building the chart is one thing, getting value from it is another. Look for the biggest "cliffs" - the most significant percentage drops from one stage to the next.

• Big drop-off from Sessions to Product Views? Your homepage or category pages may not be compelling enough, or your navigation might be confusing.

• Huge drop-off from Added to Cart to Purchased? You likely have friction in your checkout process. Are your shipping costs a surprise? Is account creation mandatory? A/B test these elements.

Use controls like the Date range control and Filter control to make your funnel interactive. Add a filter for "Campaign" or "Default channel grouping" to see how different marketing channels compare. Does your Google Ads traffic convert at a higher rate than Facebook Ads traffic? This is where your funnel graduates from a static image to a true analytical tool.

Final Thoughts

Turning a stacked bar chart into an insightful funnel in Looker Studio is a fantastic workaround that gives you full control over how you visualize your conversion process. This approach lets you quickly identify the leaks in your customer journey so you know exactly where to focus your optimization efforts.

While the process of creating custom metrics and workarounds gets the job done, it's a very manual way to answer what feels like a simple business question. That's why we built Graphed. Instead of logging into different platforms, creating calculated fields, and building clever hacks, you can simply ask for the insights in plain English. We let you securely connect tools like Google Analytics and Salesforce, ask "Show me a funnel chart comparing sessions, signups, and new customers this quarter for traffic coming from Google Ads," and get a real-time, interactive dashboard in seconds. We automated the data-wrangling so you can get straight to the answers.