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How to make a line graph in Excel, and when not to

The mechanics of how to make a line graph in excel take one sentence: select the data, Insert › Recommended Charts, choose the line chart, OK. The question worth a page is whether a line chart is the right shape for what you have — and Microsoft answers that in a sentence too, on a page that sits below four tutorial sites which do not mention it.

Here is what that means in practice. Suppose you have rainfall in one column and a pollution reading in the other, and you want to see whether one tracks the other. Put that on a line chart and Excel does not use your rainfall figures as positions at all. Microsoft’s own worked example spells out the result: “Because categories were not provided in the data, they were automatically generated, for example, 1, 2, 3, and so on. This is a good example of when not to use a line chart.” The chart looks fine. It is answering a different question from the one you asked.

Dates are the exception, and it is the exception that saves the line chart for most ordinary work. A line chart’s category axis can be a text axis or a date axis, and Microsoft describes the date axis as one that “displays dates in chronological order at specific intervals or base units, such as the number of days, months, or years, even if the dates on the worksheet are not in order or in the same base units”. So irregular dates are placed correctly. It is irregular numbers that get flattened into 1, 2, 3.

Which gives a short test before you draw anything. Are the things along the bottom dates, or names, or numbers? Dates and names are what a line chart is for. Numbers mean you probably want a scatter chart, and Microsoft’s list agrees: use one when you want to “change the scale of the horizontal axis”, use a logarithmic scale, “show patterns in large sets of data”, or “compare large numbers of data points without regard to time”.

The wording varies. How to create a line chart in excel, how to make a line graph in excel, line chart against line graph — Microsoft says chart, most people say graph, and it is one feature with one rule about what belongs on the horizontal axis.

Markers, briefly. Excel offers the line with or without dots at each reading, and Microsoft gives the rule rather than leaving it to taste: markers help “especially when you have many data points and the order in which they are presented is important”, but “if there are many categories or the values are approximate, use a line chart without markers”. Dots claim precision. If the numbers are estimates, leaving them off is the more honest drawing.

On stacked lines. Excel offers stacked and 100% stacked variants, described as showing “the trend of the contribution of each value over time”. They are harder to read than they look, for the same reason stacked bars are: only the bottom band sits on a flat baseline, so every line above it is riding on the ones below and its own shape is not what you see.

Every quoted rule and description above is from Microsoft’s own Excel documentation, read on 22 August 2026 and listed below. The three-way test for what sits along the bottom axis, and the reading of what each empty-cell option implies, are ours.

What this tower will not do

It will not present the line chart as the default chart. Microsoft gives a one-line rule for when it is the wrong one, and this floor leads with it.

It will not let a missing reading be drawn as a zero without saying so. That is a setting, and the page says where it lives.

And it will not recommend a charting add-in for something that is one entry on the Insert tab. What holds instead is simple: the rule about numeric x values, the axis descriptions and the empty-cell options are quoted from Microsoft’s own Excel documentation, with the date each page was read.