How to Make a Population Pyramid in Tableau

A population pyramid is a powerful way to visualize the age and sex distribution of a population, but building one in Tableau can feel a bit counterintuitive. You're essentially creating two bar charts and pointing them in opposite directions. This guide will walk you through the entire process step-by-step, including a clever trick with a calculated field to get the perfect result.

What is a Population Pyramid?

Before we build, let's quickly cover what we're making and why it's useful. A population pyramid is a pair of back-to-back horizontal bar charts, one for males and one for females, stacked by age group. The x-axis shows the population count (or percentage), and the y-axis shows the age cohorts (e.g., 0-4 years, 5-9 years, etc.).

This visualization is fantastic for answering questions like:

• What does our customer base look like by age and gender?
• Is our audience younger, older, or evenly distributed?
• Are there significant differences between male and female populations in certain age groups?

Marketers use this to understand target demographics, city planners use it for resource allocation, and researchers use it to analyze societal trends.

Step 1: Get Your Data Ready

Your data structure is the most important part of this process. For a population pyramid, Tableau needs your data to be "tall" rather than "wide." This means you should have at least three columns:

• Age Group: A dimension that defines your age cohorts (e.g., "18-24", "25-34").
• Gender: A dimension that contains your two groups (e.g., "Male", "Female").
• Population: A measure that contains the count or number of people for each specific age and gender group.

Your data in a spreadsheet should look something like this:

If your data is "wide" (e.g., a column for Male Population and a separate one for Female Population), you'll need to pivot it in Tableau's data source tab before you start. Simply select the columns you want to pivot, right-click, and choose Pivot.

Step 2: Build the Basic Bar Chart in Tableau

Once your data is connected and structured correctly, it's time to build the foundation of your chart on a new worksheet.

1. Drag your Age Group dimension to the Rows shelf.
2. Drag your Population measure to the Columns shelf. Tableau will automatically aggregate this as a SUM.
3. Drag your Gender dimension to the Color tile on the Marks card.

At this point, you should have a stacked or side-by-side horizontal bar chart. It’s a good start, but it doesn't have the mirrored "pyramid" effect yet. Everything is pointing to the right.

Step 3: The Secret Sauce - The Calculated Field

To create the pyramid shape, we need to make one of the gender's bars go left (negative) and the other go right (positive). This is where a simple calculated field comes in. We’ll tell Tableau: if the gender is "Male" (or whichever group you want on the left), make its population number negative.

How to Create the Calculated Field:

1. In the top menu, go to Analysis > Create Calculated Field.
2. Name your new field. Something intuitive like "Population (split)" works well.
3. In the formula box, enter the following logic. Make sure to replace [Gender] and [Population] with the exact names of your fields.

IF [Gender] = "Male" THEN -[Population]
ELSE [Population]
END

This formula checks each row. If the 'Gender' is "Male," it takes the Population number and multiplies it by -1. If it's anything else (i.e., "Female"), it leaves the number as is. Click OK to save the calculated field.

Step 4: Swap the Fields and Build the Pyramid Axis

Now, let's use our new creation.

1. In your worksheet, find your new calculated field, "Population (split)", in the Measures pane.
2. Drag "Population (split)" and drop it directly onto the SUM(Population) pill that's currently on your Columns shelf. This will replace the old measure with your new one.

Voilà! You should now have a pyramid shape. The bars for males are pointing left, and the bars for females are pointing right. However, you’ll notice a problem: the horizontal axis at the bottom shows negative numbers, which can be confusing for your audience.

Step 5: Clean Up and Format a Professional Look

This final step is all about polishing your visualization until it’s clear, professional, and easy to read.

Fix the Negative Axis Labels

Nobody wants to present a chart with "-2,000" on it. Let's make those numbers positive.

1. Right-click the axis at the bottom of your chart (where you see the negative numbers).
2. Select Format….
3. In the Format pane that appears on the left, make sure you're in the Axis tab, then navigate to the Numbers dropdown.
4. Choose Custom.
5. In the format box, enter the following custom format code: #,##0, #,##0

This code tells Tableau how to format positive and negative numbers. The format before the semicolon applies to positive numbers, and the format after applies to negatives. By making them identical, we strip the negative sign away, leaving clean numbers on both sides of our central axis.

Improve Tooltips

If you hover over the left side of your chart now, the tooltip will still show the negative population value. Let’s fix that.

1. Click on the Tooltip tile on the Marks card.
2. In the Edit Tooltip dialog box, you’ll see the field SUM(Population (split)). Highlight this and find the original, positive measure: SUM(Population).
3. Replace the negative value with the positive one, so it shows the actual count correctly. Click Insert to find and add the correct field if needed.
4. Click OK. Now your hover-over data will be correct.

Final Touches

A few last tweaks can go a long way.

• Sort Your Age Bins: Make sure your age groups are in the correct logical order (youngest at the bottom or top, depending on your preference). You can do this by dragging the labels in the Rows shelf or setting a custom sort order.
• Add Labels: Drag the Gender dimension to the Label tile on the Marks card. Then, in the Columns shelf, right-click the "Population (split)" pill and select Quick Table Calculation > Percent of Total. This shows the percentage breakdown, which is often more useful than absolute numbers.
• Adjust Colors: Click the Color tile and choose shades that are colorblind-friendly and fit your brand or report's style guide.
• Write Clear Titles: Give your worksheet a descriptive title like "Customer Demographics by Age and Gender" or "Population Distribution of the United States." Add a subtitle if further clarification is needed.

Final Thoughts

Building a population pyramid in Tableau takes a few specific steps, but it’s a brilliant way to compare demographic distributions side-by-side. The key is using that simple calculated field to reverse the direction of one bar set and then cleaning up the axis formatting for a polished, professional look that anyone can understand.

While creating charts like this in a tool like Tableau is incredibly powerful, it often requires knowing these specific quirks and step-by-step processes. As a team, we found that building reports and dashboards often felt more like data wrangling than getting answers. That’s why we created Graphed. It allows you to skip the manual setup and simply ask for what you need in plain English. For example, you could just ask, "Create a population pyramid showing my Shopify customers by age and gender," and get a live, interactive visualization instantly - no calculated fields or axis formatting required.