Grouped Bar Charts

A grouped bar chart — also called a clustered bar chart — places several bars side by side within each category so you can compare multiple data series at once. Where a plain bar chart shows one value per category, a grouped chart shows several: each category becomes a small cluster of bars, one bar per series, with the series distinguished by colour. It is the go-to format when you want to ask how do these series compare, both within each category and across categories? — for example, two or three measures recorded for the same set of groups.

How a grouped bar chart works

Categories run along one axis — typically the horizontal axis for vertical bars. Within each category, the chart draws one bar per series, packed together as a tight cluster with a gap separating the clusters. A shared colour identifies each series across every category, and a legend maps colours to series. The value axis starts at zero, so a bar twice as tall really does represent twice the value. Because all the bars sit on the same baseline, you can read two comparisons from one picture: the bars within a cluster against each other, and the same-coloured bar across clusters.

That dual reading is the format's strength and its main demand on the reader. Keep the number of series small and the colours distinct, and both comparisons stay easy. Let either grow and the clusters turn into a thicket.

When to use a grouped bar chart

• Comparing a few series across categories. Two to four measures recorded for the same set of groups, where you want them side by side rather than summed.
• The individual values matter. Grouped bars keep every value on the same baseline, so each one can be read and compared precisely.
• Within-category contrast is the point. "In this category Series 1 leads, but in that one Series 2 does" is a takeaway grouped bars show clearly.
• No meaningful total. When the series are not parts of a whole and adding them would be nonsense, side-by-side bars are correct where stacking would mislead.

Grouped vs. stacked bars

The two are easy to confuse because both show multiple series. The difference is what each makes easy. A grouped chart sets the bars side by side, so every value rises from the same baseline and direct comparison is accurate — but the total for a category is not shown. A stacked chart piles the series into one bar, so the total is obvious and you can see each part's contribution to it — but only the bottom segment starts at zero, which makes comparing the upper segments harder. Choose grouped when comparison matters most; choose stacked when composition and totals matter most.

How to read a grouped bar chart

First read the legend so you know which colour is which series. Then pick a reading direction. To compare series within a category, look at the bars in a single cluster and judge their heights against each other. To track one series across categories, follow a single colour from cluster to cluster — your eye will naturally line up the same-coloured bars. Use the value axis, which starts at zero, to read magnitudes, and lean on data labels for anything that looks close. Because the bars share a baseline, height differences are trustworthy in a way that pie or radar comparisons are not.

Variants

Grouped bars can be drawn vertical (columns) or horizontal; horizontal is handy when category names are long. Small multiples — repeating a simple bar chart once per series in a grid — are a clean alternative when you have more series than a single cluster can hold. And some charts combine approaches, grouping a couple of clusters that are each lightly stacked, though that quickly becomes hard to read. For most cases, a straightforward cluster of two to four bars per category is the clearest choice.

Common mistakes to avoid

Make a grouped bar chart

Ready to build one? The stacked bar chart maker handles grouped (clustered) bars too — enter your categories and series or paste a CSV, switch between grouped and stacked, recolour, and export a PNG or SVG — free, no signup, no watermark.