Excel: 100% Stack Bar Chart, the bars are not plotting correct for few combination of values

Question

Please look at the image below: How can orange bar in the first chart be that big. This pattern repeats even if I make both values half like 105, 21 or 53, 10 etc.

As soon as value is value is 43 the chart starts behaving fine.

Thanks.

Answer 1

Excel is changing the axis (that you don't have displayed) automatically to what it thinks is a relevant range. However, this range is probably something like 75% to 100% as in the following picture (with the axis displayed):

While this seems to not make sense for the purpose of a 100% stacked bar chart, this is nonetheless what Excel tries to do.

To fix it, go to Primary Horizontal Axis options and change the Minimum from "Auto" to "Fixed" and set the value to 0. You might also want to set the Maximum to "Fixed" and set the value to 1. See options pictured below:

Answer 2

Excel seems to start doing its auto axis adjustment once one of the numbers is less than about 20% of the other number.