How to Reduce Space Between Bars in Tableau

A great-looking bar chart often comes down to the details, and the empty space between your bars can make or break a visualization. While Tableau's defaults are smart, they sometimes leave you with awkwardly wide gaps that make data harder to compare and your dashboard look unfinished. You can fix this in just a few clicks.

This article will walk you through several easy and effective methods to reduce the space between bars in Tableau. We’ll cover everything from the basic Size slider to handling dates and numbers that can completely change your chart's layout, giving you full control over your final design.

Why Bar Spacing Matters in Data Visualization

Before we jump into the "how," let's quickly cover the "why." Adjusting the space between your bars isn't just about aesthetics, it directly impacts how your audience interprets the data. Here's what you gain by controlling it:

• Improved Readability: When bars are closer together, the viewer's eye can more easily jump between them to compare heights and spot trends. Excessive white space forces more effort and can weaken the patterns you're trying to highlight.
• Better Data Density: Tighter spacing allows you to fit more information into a smaller area without it feeling chaotic. This is especially useful in crowded dashboards where every pixel counts.
• A More Professional Look: Default settings can sometimes look generic. Fine-tuning details like bar width and spacing makes your dashboards look more polished, custom, and professional.

The goal is to find the sweet spot - enough space to distinguish individual bars, but not so much that it disconnects the data points from one another.

Understanding The Core Concept: Continuous vs. Discrete Data

In Tableau, the spacing between bars is fundamentally controlled by the type of data field (or "pill") you place on the Columns or Rows shelf. It all boils down to whether the pill is Discrete or Continuous.

• Discrete Fields (Blue Pills): Think of these as individual, distinct categories. Examples include "Department" (Sales, Marketing, HR) or "Region" (North, South, East, West). When you use a discrete field, Tableau creates a separate header for each category and places the bars close to each other. Spacing is minimal by default.
• Continuous Fields (Green Pills): Think of these as values along a spectrum or timeline. Examples include "Sales" figures, profit ratios, or a range of dates. When you use a continuous field, Tableau creates an axis - a smooth line of values from a minimum to a maximum - and places marks (in this case, bars) along that axis based on their exact value. This is where you often get unwanted large gaps.

The number one reason for wide spaces between bars is using a continuous (green) pill for your categories or date periods when a discrete (blue) pill would be more appropriate.

Method 1: The Quick & Easy Size Slider

The most direct way to change bar width and, by extension, the spacing, is by using the Size card on the Marks pane. This method works best when your categories are on a discrete (blue) pill.

Let's say you're building a simple bar chart showing Sales by Sub-Category from the "Orders" table.

1. Drag your dimension (e.g., Sub-Category) to the Columns shelf. Since it’s a text field, it will appear as a blue, discrete pill.
2. Drag your measure (e.g., Sales) to the Rows shelf. It will appear as a green, continuous pill, creating a vertical axis.
3. You'll now have a standard bar chart. By default, the bars might be quite thin.
4. Find the Marks card. Click on the button labeled Size.
5. A slider will appear. Drag the handle to the right. As you do, you'll see the bars get wider, directly reducing the empty space between them.

This is the simplest solution and often all you need. However, if you drag this slider all the way to the right and still have too much space, or if the slider seems to have no effect, it's almost certainly because you're using a continuous field on your axis.

Method 2: Convert Continuous Fields to Discrete

This is the most powerful technique for closing gaps, especially when working with dates or numerical bins. Tableau often defaults dates to be continuous, which creates a timeline axis and big spaces if you're missing data for certain periods (e.g., no sales in March).

Fixing Spacing for Dates

Imagine you have a chart showing monthly sales. If you drag your "Order Date" field to columns, Tableau might default to YEAR(Order Date). If you right-click on it and change it to Month, you'll likely get a continuous green pill for the month, creating an axis from January to December.

Here’s how to fix the resulting gaps:

1. Right-click on the green date pill (e.g., MONTH(Order Date)) that's on your Columns shelf.
2. In the context menu, near the bottom, you'll see a section with two versions of your date part (Day, Month, Quarter, etc.). The first group represents discrete date parts, and the second represents continuous ones.
3. Select the very first Month option in the menu (e.g., MAY). This is the discrete version. Your pill will immediately turn blue.

The chart will transform. Instead of a continuous axis, you'll now have a separate header for each month that has data. The bars will cluster together, instantly removing all the empty space. From here, you can go back to Method 1 and use the Size slider to fine-tune the exact spacing.

Fixing Spacing for Numbers

The same logic applies if you're using a numerical field on your axis. For instance, you may have binned ages into groups ([18-25], [26-35], etc.) or are displaying sales by a numeric priority level. If your numeric field is continuous (green), there will be gaps.

To fix this, right-click the green numeric pill on the Columns shelf and select Discrete. The pill will turn blue, the axis will convert into headers, and the bars will be grouped together, allowing the Size slider to work as intended.

Method 3: Adjust the Axis "Tick Marks" for Fixed Units (Advanced)

Sometimes you need to keep a continuous axis but want more control over how bars are positioned. For instance, when visualizing data over a specific time series, you can't always just make it discrete. In these cases, you can adjust the tick marks on the axis to manage spacing.

This is an advanced technique that tells Tableau exactly how wide each "slot" for a bar should be. Let's use an example of a bar chart showing sales by week along a continuous axis.

1. Create your bar chart with a continuous date field (green pill for an exact date or week) on the Columns shelf.
2. Right-click on the horizontal date axis at the bottom of your chart and select Edit Axis...
3. A new window will pop up. Go to the Tick Marks tab.
4. Under the "Major Tick Marks" section, change the setting from "Automatic" to Fixed.
5. Here’s the key part: set the Tick Origin to a date your data starts on or near. For the "interval," define your desired unit. If your chart is showing daily data, for example, you can set the ticks to fire every 1 day.
6. Now go to the Size card on your Marks pane. You will see an option for fixed-width bars. You’ll want to select that.
7. You will now see another field under “size” — Set the bar size in days. Your choice of what you put in the box will determine your bar chart's spacing. You’ll choose a number in days, so 1 day will be no spacing and any other fractional number will be for reducing bar spacing.

This tells Tableau to create a uniformly slotted space for each day along the axis. You still use the Size slider to determine the actual width of the bar within that slot. This method gives you pixel-perfect control over the rhythm and pacing of marks along a continuous axis, ensuring a consistent look regardless of missing data points.

Final Thoughts

Controlling the spacing between bars may seem like a minor tweak, but it's a foundational skill for creating clear, effective, and professional dashboards in Tableau. By understanding the core difference between discrete and continuous fields and knowing how to use the Size slider and axis settings, you can easily transform a cluttered or sparse chart into a clean and readable one.

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