In Excel: put time or ordered categories in the first column, values in the next column, select both, then Insert ▸ Line or Area Chart ▸ Line.
Arrange the x-axis labels in the first column and the values in the next column.
Select only the label and value range, excluding totals.
Choose Insert ▸ Line or Area Chart ▸ Line.
Add a chart title, axis labels and markers when the individual points need to be visible.
What this does
A line graph connects values in order, usually across time, so the slope makes direction and change visible. The first column should hold dates, months or ordered categories; the second holds the values to plot. Excel treats each additional numeric column as another line, which is useful for comparing series but messy if totals or helper columns are accidentally selected. Keep the inputs visible and clearly labelled and the whole thing stays auditable — anyone who opens the file later, including you, can see at a glance exactly what feeds the result and change one assumption without hunting through the formula. The difference between a quick fix and a sheet you can trust is the extra minute you spend validating “excel line chart add an average line”. Start on a copy or a tiny sample, keep the affected chart visible, and compare the result with the tool above before you touch the real workbook. When this is a ribbon command, the selection matters more than the button: confirm the range, apply the command, then spot-check the output before saving. The point is a visual that makes the number obvious at a glance, but the practical win is that someone else can open the file and understand what happened without asking you.
A worked example
Months Jan through Jun are in A2:A7 and sales 42, 51, 48, 61, 67, 73 are in B2:B7. Select A2:B7, choose Insert ▸ Line Chart, and Excel draws a six-point line rising from 42 to 73. Add markers if individual months matter, and format the vertical axis to start at zero only when that supports the story rather than flattening the change. Line graphs are strong for trends: monthly sales, weekly traffic, running totals, error rates, production output and any metric where readers need to see direction over a sequence. A practical tip before you scale it up: build it once on a small block of test data, confirm the number against the tool on this page, and only then point it at your real sheet. That one habit catches almost every mistake while it is still cheap to fix, long before a wrong figure reaches a report or a colleague.
In Google Sheets
If you are in Google Sheets rather than Excel, the good news is that the formula shown here is identical and the workflow barely changes — menus sit across the top instead of in a ribbon, and a few function names differ slightly, but anything you build here moves across with little or no rework. The aim was to get you unstuck fast and leave you a little more capable than a copy-paste would. The answer is at the top, the tool proves it, and the detail above shows why it holds — so the next time a colleague asks, you can answer without reaching for search. The short version of “excel line chart add an average line”: the answer is at the top of this page, the tool proves it on your own numbers, and the sections above explain why it holds so the next variation does not stump you. Excel rewards people who reference cells instead of typing values and who keep inputs separate from formulas, because that is what makes a result you can audit months later. Build it once, deliberately, with the live tool as a check, and you convert a one-off lookup into a reusable skill — which is the whole point of learning the why and not just the what.
Common mistakes
- Using a line chart for unordered categories, where a bar chart would compare values more honestly.
- Including a total row, which creates a sudden fake spike at the end.
- Letting Excel treat text dates as categories; convert them to real dates when spacing matters.
- Plotting too many series at once, turning the chart into unreadable crossing lines.
Frequently asked questions
When should I use a line graph?
Use it for ordered data, especially time series, where the change from one point to the next matters.
How do I add a second line?
Place the second value series in another column beside the first, include it in the selected range, and Excel plots it as a separate line.
Line chart or scatter plot?
Use a line chart for ordered categories or dates; use a scatter plot when both axes are numeric measurements.
Other ways people ask this
This is also commonly searched as “add an average line to excel chart”, “add average line to excel chart”, “how to add an average line in excel chart” and “how to add average line in excel chart”. They describe the identical operation, so you are in the right place no matter how you phrased it.
Why do people search for this in so many different ways?
Because the same task has many names. “add an average line to excel chart”, “add average line to excel chart”, “how to add an average line in excel chart” all point at the one operation explained on this page, which is why they all lead here.