Excel Combo Chart Bar Width: How to Change Gap Width

To change bar width in an Excel combo chart, select a column series, open Format Data Series, and adjust Series Options > Gap Width. Lower the gap-width percentage to make the columns wider; raise it to make them narrower. This applies to column series in the chart, not to a line series.

What “bar width” means in a combo chart

Excel’s combo charts combine two or more chart types, commonly clustered columns and a line. In spreadsheet terminology, vertical bars are usually called columns, while horizontal bars are called bars. People often use “bar width” for either, but the relevant control is generally the same: Gap Width.

Gap Width sets the amount of empty space between category groups relative to the width of a column. A lower percentage leaves less space and makes columns look broader. A higher percentage adds more space and makes them look slimmer. It is not a direct measurement in pixels or a setting for the chart’s overall width.

For example, a combo chart might show monthly revenue as columns and a moving average as a line. Changing Gap Width can make the revenue columns easier to see, while the line’s thickness and appearance remain controlled by separate line-formatting settings. If the combo chart contains no column or bar series, Gap Width will not be available for its line series.

Change Gap Width in Excel for Microsoft 365 on Windows

Use these steps in Excel for Microsoft 365 on Windows:

Click the combo chart, then click one of the columns once. A single click normally selects the entire data series; clicking the same column again selects just that individual data point.
Right-click the selected column and choose Format Data Series. The formatting pane opens at the side of the Excel window.
In the pane, select Series Options (the chart-series options icon, if the pane displays icons).
Find Gap Width. Enter a smaller percentage to widen the columns or a larger percentage to narrow them. You can also use the slider if it appears.
Click elsewhere in the chart to review the result. Reopen the pane and adjust the percentage if the columns are still too wide or too narrow.

As a practical starting point, try reducing a setting such as 150% to 75% if columns look too thin. These are example values, not recommended defaults for every chart; the right spacing depends on the chart’s size, number of categories, and number of column series. A value of 0% removes the gap between category groups, while a large value creates more separation.

You can also select the series and use the chart-formatting controls on the ribbon, but the Format Data Series pane makes the exact Gap Width value easiest to locate and edit. If the chart is selected but the pane shows chart-area or plot-area options, select a column again before opening the pane.

How Gap Width affects column size

Gap Width is a spacing ratio, not a promise that each column will have a particular physical width. The columns’ apparent width also depends on the available plot-area width, how many categories are shown, and how many column series are grouped in each category. Consequently, the same percentage can look different in a small chart and a wide chart.

Suppose a chart shows 12 months and one column series. At a high Gap Width, the columns may look thin because Excel leaves conspicuous spaces between the months. Reducing the setting makes each column broader within the available space. If you add more months or another column series, the available room per category is divided differently, so the columns can appear narrower even though the percentage has not changed.

Excel adjusts the chart to fit its plot area. Resizing the chart can therefore change the columns’ visual width without changing Gap Width. If the chart is crowded, widening the chart or reducing the number of displayed categories may improve readability more effectively than setting the gap close to zero.

Multiple column series, overlap, and combo-chart axes

When a combo chart contains more than one column series—for example, actual sales and budget—the columns may sit side by side within each category. Gap Width controls the spacing between category groups; it does not by itself decide how much those column series overlap. For that, Excel provides Series Overlap in the series options for supported column chart groups.

Series Overlap changes the relative placement of columns in the same category. A negative value separates them, while a positive value brings them closer together and can make them overlap. If columns appear stacked on top of one another unexpectedly, inspect Series Overlap as well as Gap Width. The exact visual result also depends on whether the series are clustered or stacked.

Combo charts can place a series on a secondary vertical axis, often because a line uses a different scale from the columns. A secondary axis can make the chart easier to interpret, but it does not create a general-purpose “bar width” control for every series. If the chart has column series in different chart groups or on different axes, select the particular columns you want to format and inspect their own Series Options. Separate groups may not line up as one set of columns, so changing spacing can expose gaps or overlaps rather than produce a single uniform set of bars.

For a straightforward layout, keep the column series together in one column chart group and use the line for the series that needs a different visual scale. If you need a secondary axis, check the category alignment after changing Gap Width, especially when both axes contain column series. The chart’s appearance depends on the combination of chart types, not just on one percentage.

When changing Gap Width does not fix the chart

A width adjustment may not solve the problem if the chart is crowded for another reason. Check these common causes before making the columns extremely wide:

Too many categories: A long list of dates or names leaves less room for each category. Consider showing a shorter date range or summarizing the data.
Several column series: Multiple side-by-side series divide each category’s available space. Remove unnecessary series or consider a different chart layout.
Wrong chart type: If a series is a line, area, or scatter series, it does not have column width to adjust. Confirm that the series you intend to widen is actually a column series.
Single data point selected: Clicking a column twice may select only that point. Click once to select the complete series, then reopen Format Data Series.
Small plot area: A large legend, title, or axis labels can reduce the area used to draw the data. Move or resize those chart elements, or enlarge the chart.
Columns overlap or misalign: Review Series Overlap and whether series are assigned to primary or secondary axes. Gap Width is not an axis-alignment setting.

Also distinguish a category-axis problem from a width problem. If dates are being treated as separate text categories or labels are skipping, changing Gap Width will not correct the axis interpretation. Format the axis or adjust the source data and category settings as appropriate, then revisit column spacing.

Choosing a useful width and checking readability

There is no single ideal Gap Width. The goal is to make comparisons clear without merging neighboring categories visually. Wider columns can help when there are only a few categories, but a very small gap can make a chart look like one continuous block. Narrower columns can help when many categories need to remain distinct.

After changing the setting, check the chart at the size at which readers will actually view it. A chart that looks balanced on a large monitor may become cramped when pasted into a report or displayed in a narrow worksheet column. Confirm that:

neighboring categories are still easy to distinguish;
columns for separate series can be compared without confusion;
the line remains visible over or beside the columns; and
axis labels and data labels do not collide with the wider columns.

If data labels are difficult to read, changing their position or removing unnecessary labels may help more than further widening the columns. Likewise, if the line is obscured by columns, adjust the line’s formatting or chart design rather than expecting Gap Width to change the line. For a chart intended for printing, check the print preview because the final printed size can alter how crowded the plot appears.

Excel for Mac and Excel for the web

In Excel for Mac, the basic approach is the same: select a column series, open its formatting options, and change Gap Width under Series Options. Ribbon and pane placement can vary slightly between Mac releases, so using the series’ context menu and choosing Format Data Series is a useful route when the ribbon layout differs. The exact Windows menu presentation should not be assumed to match every Mac build.

Excel for the web also supports chart formatting, but the available controls and pane layout can differ from the Microsoft 365 Windows desktop app and may change as the web app is updated. If Gap Width is not exposed in the browser interface, open the workbook in the desktop app to make the adjustment. Formatting saved in the desktop workbook will generally be reflected when the file is viewed online, though review the chart after saving.

Frequently Asked Questions

Can I change the width of just one bar in a combo chart?

Gap Width is a series or chart-group spacing control, not a way to set an arbitrary width for one individual column. Selecting one data point may let you format that point’s fill or border, but it does not provide a separate physical-width setting. To make one value stand out, use a different color, data label, or another supported point-formatting option.

Does a lower Gap Width make the bars wider?

Yes. Lower Gap Width means less space between category groups, so the columns generally appear wider. A higher percentage means more space and narrower-looking columns. The precise appearance still depends on chart size, category count, and the number of column series.

Why can’t I find Gap Width?

First confirm that you selected a column or bar series rather than the chart area, an axis, or a line series. Right-click a column and choose Format Data Series, then look under Series Options. If the selected series is not a column or bar chart type, a width setting will not apply.

Does Gap Width control the space between two series in the same month?

Not directly. Gap Width primarily adjusts spacing between category groups. For side-by-side column series within the same category, check Series Overlap and the chart’s clustered or stacked arrangement as well.

Can I make columns wider by resizing the chart?

Often, yes. A wider plot area gives Excel more horizontal room, which can make columns appear broader at the same Gap Width. Resizing is not an exact substitute for changing the setting, because the number of categories and series still affects how Excel allocates space.

Does changing Gap Width affect a combo chart’s line?

No. Gap Width changes spacing for column or bar series, not the line’s thickness or marker size. Format the line series separately if you want to change its color, line width, or markers.

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