What is a segmented bar graph? Stacked bar charts explained

Segmented bar graphs turn up everywhere, from statistics exams to quarterly business reviews. They pack a lot into one chart, which is their strength and the source of most mistakes. This guide covers how to read one, the two main types, and when another chart would do the job better.

How to read a segmented bar graph

1. Read the whole bar first. Its height (or length, if horizontal) is the total for that category: Q3 revenue of $198K, say.
2. Check the legend or labels. Each color is one part of the total, such as espresso drinks, cold brew and pastries.
3. Compare the bottom segment across bars. It starts at zero, so this comparison is as easy as a normal bar chart.
4. Judge the other segments by their own height, not by where they end. A middle segment that finishes higher isn’t necessarily bigger, because it starts higher too.

That last point is the catch. Only one segment shares the baseline, so comparing the middle parts across bars means estimating floating lengths. That’s why the best segmented bar graphs keep the most important part at the bottom, and label the values that matter.

The two types: stacked and 100% stacked

There are two versions, and choosing the right one depends on whether the totals matter.

In statistics, the 100% version is the classic segmented bar graph for comparing two categorical variables. Survey 400 customers about their preferred device, split them by age group, and each bar shows the percentage of that age group choosing desktop, mobile or tablet. Because every bar is 100%, groups of different sizes become comparable.

For example: of 180 customers aged 18–34, 112 preferred mobile (62%), 50 desktop (28%) and 18 tablet (10%). Of 220 customers aged 35 and over, 77 preferred mobile (35%), 121 desktop (55%) and 22 tablet (10%). Two 100% bars make the shift from mobile to desktop obvious, even though the groups are different sizes.

In business reporting, the absolute version is more common, because the totals usually matter. If cold brew grew from 19% to 35% of revenue but revenue also grew, you want both facts on the slide.

When to use a segmented bar graph

• You want the total and its breakdown in one view, such as quarterly revenue split by product line.
• You're comparing how a mix differs across groups: answers by region, traffic sources by month.
• There are two to five segments, and the category order is meaningful or consistent.
• Your values are all positive. Stacking negative numbers gets confusing fast.

If what matters is how each part compares across categories, a grouped bar chart puts every series on the baseline instead. Our grouped vs stacked bar chart guide walks through that decision.

Common mistakes to avoid

• Too many segments. Eight slices of similar purple aren’t a chart. They’re a color-matching exercise. Group the small parts into Other.
• Shuffling segment order between bars. Keep the same order and the same color for each part, everywhere in the report.
• Hiding the totals. With absolute stacks, add a total label above each bar so nobody has to add up segments in their head.
• Using 100% stacked when totals differ hugely. A 100% bar for 12 responses looks as solid as one for 1,200. Note the counts.
• Putting the key segment in the middle. Move the part you want compared to the bottom, on the baseline.

Segmented bar graph vs pie chart and grouped bars

A pie chart shows the composition of one whole. A segmented bar graph shows the composition of several wholes side by side, which is almost always the more useful comparison in a report. If you find yourself making three pie charts in a row, a 100% segmented bar graph will make the same point more clearly.

Grouped bars trade the total for precision: every series sits on the baseline, so each part is easy to compare, but there’s no bar that shows the whole. Stack when the total matters. Group when the parts do.

How to make a segmented bar graph in Lightchart

The Lightchart stacked bar chart maker builds one from a pasted table:

1. Paste three columns: the category (Quarter), the part (Product line) and the value (Revenue).
2. Open the bar settings and choose Stacked, or Stacked % for a 100% segmented bar graph.
3. Turn on Show Total Values, apply your brand palette, and export a 2× PNG.

Before you export, check the title. “Cold brew grew to a third of revenue” tells the reader which segment to watch. “Revenue by product line” makes them work it out.