← All Kits · Excel Kit

Stacked or Grouped Bars: What Each One Lets the Reader Compare

Michael Nocito · Updated August 2026 · Every number on this page was worked before it was published

Stacked or grouped is not a style question. The two charts let a reader do different arithmetic, and choosing wrongly means the comparison you need is the one the chart cannot support.

What you do: ask what the reader must compare. Totals across bars, use stacked. Categories against each other, use grouped. Shares, use 100 percent stacked and label the totals separately.

The short version. In a stacked bar, only the bottom segment starts from the same line in every bar. Everything above it floats.

The table both charts are drawn from

Stacked: totals are easy, upsell is guesswork

Stack New, Renewal and Upsell and you can rank the totals instantly: East 139, North 131, South 88, West 75. You can also compare New across regions, because New sits on the floor in every bar and the eye is comparing lengths from a shared start.

Now try to answer whether North's upsell beats East's. North is 22 and East is 17, so the answer is yes, but on the chart those segments start at 109 and 122 respectively. The reader has to compare two short blocks floating at different heights, which is a task human vision is measurably bad at. They will get it wrong, or more often they will simply not try.

Grouped: every category comparable, no totals

Draw three bars per region and every segment now starts at zero. North against East on upsell is immediate, and so is West's unusual shape: it is the only region where New beats Renewal, 39 against 26. That is the actual finding in this table, and the stacked version buries it.

What is gone is the total. Nowhere on a grouped chart can a reader see that East is 139. If they need the total, it goes in the label or in a small table beside the chart.

100 percent stacked: mix only

Rescale every bar to full height and read the shares: North is 37 percent new, South 35 percent, East 37 percent, West 52 percent. West's shape is now obvious and its size is invisible, which is the trade the chart makes on purpose. Always print the total next to each bar label, otherwise a 75 and a 139 sit side by side looking identical.

The choice, in one table

Rules that apply to both

1. Order the segments deliberately and keep that order everywhere. The most important segment goes on the floor of a stacked bar, because it is the only one that can be compared.
2. Sort the bars by value unless the categories have a natural order such as months. See sorting your bars.
3. Cap the segments at four, plus other. A seven-segment stack is a legend with decoration attached.
4. Keep the colour meaning fixed across every chart in the pack. Renewal is one colour in the whole deck or it is noise.
5. Start at zero. Bars encode length. There is no version of this chart with a truncated axis that is honest.

Doing it in Excel

1. Lay the data out with categories as columns and groups as rows, exactly as the table above.
2. Insert, Column, then Clustered for grouped, Stacked for stacked, or 100% Stacked for shares.
3. To reorder segments, use Select Data, then the up and down arrows on the series list. Reordering columns in the sheet works too and is easier to keep straight.
4. Add data labels to the segments you want compared, which partly rescues the floating-segment problem when a stacked chart is unavoidable.
5. For totals on a stacked chart, add a transparent total series and label it, or put the totals in the axis labels.

How to apply this to your own work

1. Take your most-used stacked chart and write down the question it is meant to answer. If the answer needs a segment that is not on the floor, redraw it.
2. Redraw one stacked chart as grouped and see whether any row surprises you. The surprising row is why the chart existed.
3. Count the segments. Anything above four gets an other category or becomes small multiples.
4. Check the segment order is the same on every chart in the pack. It usually is not.
5. If you use 100 percent stacked, add the totals to the labels today. That is a two minute fix with a large payoff.

The one habit to keep

Before choosing, write the sentence you want the reader to leave with. "East sells most" points at stacked. "West sells differently" points at grouped. The sentence chooses the chart, and it also turns out to be the title.

Which segment is sitting on the floor of your stacked chart, and is it the one that matters?