The simplest way to add a line to an existing graph

Open your spreadsheet with the graph already in it. Click once on the graph itself — you'll see a border appear around it with small squares at the corners and edges. Right-click on the graph and select Edit Data. A panel will open on the right side showing the data your graph is using. Find the row or column you want to add as a new line, and check the box next to it. The line appears on your graph when ready.

If you don't see the data panel, you can open it another way: click the graph, then go to the Design tab at the top of the screen (this tab only appears when a graph is selected). Click Select Data in the left corner. A dialog box opens. Click Add under the "Legend Entries (Series)" section on the left. Type or paste the data range you want to add — for example, Sheet1!B2:B10 if your new line's numbers are in column B, rows 2 through 10.

The new line will use a different color automatically so you can tell it apart from the existing lines. If the colors are hard to see or you want to change them, click the line itself once it's on the graph, then right-click and choose Format Data Series.

Key Takeaways

  • The fastest method is to click the graph, right-click, select Edit Data, and check the box next to the data you want to add.
  • If Edit Data doesn't appear, use the Design tab at the top, then Select Data, then Add to enter the data range manually.
  • Excel assigns each new line a different color so the lines stay visually separate on your graph.
  • You can change a line's color, thickness, or style by right-clicking the line and choosing Format Data Series.

When you need to add data from a different sheet

If the numbers for your new line live on a different sheet in the same workbook, the process is the same, but you need to type the sheet name in front of the range. Click the graph, go to Design > Select Data > Add. In the dialog that opens, type the range like this: Sheet2!C5:C15 (replace "Sheet2" with your actual sheet name, and C5:C15 with your actual range). Excel will pull the data across sheets and add it to your graph.

Make sure the numbers you're adding are in the same units and roughly the same scale as your existing lines. If one line shows values between 0 and 10 and you add a line with values between 1,000 and 2,000, the smaller line will flatten against the bottom of the graph and become hard to read. You can fix this by adding a second vertical axis — see the section below on that topic.

Adding a line when your data is not yet in the spreadsheet

If you want to add a line but haven't entered the numbers yet, create the data first. Type your numbers into an empty column or row, then follow the steps above to add that range to your graph. Don't try to add the line first and fill in numbers later — Excel needs the data to exist before it can plot it.

If you're adding a single point or a short series, you can also type the numbers directly into the Select Data dialog, but this is slower and more error-prone than entering them in the sheet first. For anything longer than a few values, enter them in the spreadsheet where you can see them, then add the range to the graph.

Using a second vertical axis when lines have different scales

When you add a line with very different numbers — for example, adding a line that ranges from 5,000 to 6,000 to a graph where other lines range from 10 to 50 — the new line becomes invisible because it's so far above the scale. The solution is a second vertical axis on the right side of the graph.

Click the new line once to select it (the line itself, not the whole graph). Right-click and choose Format Data Series. In the panel that opens, find Series Options and look for the option that says Secondary Axis or Plot Series On. Select Secondary Axis. The line will now use a separate scale on the right side of the graph, and both lines become visible. The right axis will show the scale for the new line, and the left axis will show the scale for the original lines.

Label your axes clearly so anyone reading the graph knows which axis goes with which line. Click the right axis numbers, right-click, and choose Format Axis to change the label or appearance if needed.

Removing a line you added by mistake

If you added a line and want to remove it, click the graph, then right-click and select Edit Data. Find the line you want to remove in the data panel on the right, and uncheck the box next to it. The line disappears from the graph when ready. If you used the Select Data dialog instead, click the line you want to remove in the "Legend Entries" list and click Remove.

Unchecking or removing a line from the graph does not delete the numbers from your spreadsheet — it only hides the line from the graph. Your data stays in the cells where you typed it.

Frequently Asked Questions

Why doesn't my new line show up on the graph?

The most common reason is that the data range you entered is wrong or empty. Click the graph, go to Design > Select Data, and check that the range you added actually contains numbers. If you typed the range manually, make sure there are no typos and that you included the sheet name if the data is on a different sheet (for example, Sheet1!A1:A10, not just A1:A10).

Can I add a line that's a formula instead of typed numbers?

Yes. Create a column with your formula (for example, a formula that multiplies another column by 2), then add that column's range to your graph the same way you would add any other data. Excel treats formulas and typed numbers the same way when building graphs.

How do I change the style of a line — make it dashed or thicker?

Click the line once to select it, then right-click and choose Format Data Series. In the panel that opens, look for Line options. You can change the thickness (called "Width"), the color, and the style (solid, dashed, dotted, etc.). Make your changes and close the panel — the line updates when ready.

What if I want to add a line that shows the average of my data?

Create a new column with a formula that calculates the average (use =AVERAGE(range)), then add that column to your graph as a new line. You can make this line dashed or a different color so readers know it's an average, not actual data.