A line graph shows change over time with a single line connecting data points

A line graph is the clearest way to show how something changes month to month, year to year, or across any other time period. You plot points on a grid — one axis for time, one for the value you're measuring — and connect them with a line. The result is a visual that makes trends obvious at a glance: rising, falling, or flat.

You can make a line graph in Excel, Google Sheets, or most other spreadsheet programs in under five minutes. The steps are nearly identical in both. You need three things: a column of dates or time periods, a column of the numbers you're measuring, and the ability to select both columns and insert a chart.

Key Takeaways

  • Organize your data in two columns: one for dates or time periods, one for the values you're measuring, with headers at the top.
  • Select both columns including the headers, then use the Insert Chart menu to create a line chart.
  • The chart will appear on the same sheet as your data and update automatically if you change the numbers.
  • You can edit the title, axis labels, and colors after the chart is created without rebuilding it.

Set up your data in two columns

Open a new spreadsheet in Excel or Google Sheets. In the first column, add a header — something like "Month" or "Date" — and list your time periods below it. In the second column, add a header for what you're measuring — "Sales," "Temperature," "Website Visits," whatever applies — and list the numbers below.

The order matters: time goes in the first column, values in the second. Start with the earliest date or period at the top and work forward. If you're tracking monthly sales, your first column might read January, February, March, and your second column might read 1200, 1450, 1380. Keep the data straightforward and clean — no extra text, no blank rows in the middle.

Select both columns and insert a chart

In Google Sheets: Click on the first cell of your time column and drag down to the last value in your second column. This selects all your data including headers. Go to the menu and click Insert, then Chart. Google Sheets will open a chart editor on the right side of the screen and show you a preview. In the Chart Type dropdown, select Line Chart. Click Insert to place it on your sheet.

In Excel: Click on the first cell of your time column and drag down to the last value in your second column. Go to the Insert menu at the top and click Chart. A dialog box opens. On the left side, click Line, then choose the first option (a line with points). Click OK. The chart appears on your sheet.

Edit the title and labels

Once the chart is created, you can change its title and axis labels. In Google Sheets, the chart editor panel is still open on the right. Click the Chart & Axis Titles tab. In the Title field, type a clear name for your graph — "Monthly Sales 2024" or "Temperature by Week." Below that, you can add titles for the horizontal axis (your time periods) and vertical axis (your values).

In Excel, double-click the chart to enter edit mode. Right-click the title at the top of the chart and select Edit Text, then type your new title. To label the axes, right-click the numbers on the left side (vertical axis) and select Add Axis Title, then type the label. Do the same for the bottom axis.

Adjust colors and line style if needed

The default colors work fine, but you can change them if you want. In Google Sheets, go to the Series tab in the chart editor. Click the color square next to your data series to pick a new color. In Excel, right-click the line itself and select Format Data Series, then choose a new color from the Fill & Line options.

If you want a thicker or thinner line, the process is similar. In Google Sheets, look for Line Thickness in the Series tab. In Excel, right-click the line and adjust the Width setting in Format Data Series. These changes are cosmetic — they don't affect the data or what the graph shows.

Update the graph when your data changes

The graph is linked to your data. If you change a number in one of your columns, the line on the chart moves automatically. You don't have to rebuild the graph. This is useful if you're tracking something ongoing — add a new month's data to your spreadsheet, and the line extends to include it.

If you add new rows of data below what you originally selected, the chart won't include them automatically. In Google Sheets, click the chart and look at the Data Range field in the chart editor — you can expand it to include more rows. In Excel, right-click the chart, select Data, and adjust the range to include your new data.

Common reasons a line graph doesn't look right

If your line is jagged or doesn't show a clear trend, check that your data is in the right order — earliest date first, latest date last. If the line is flat or missing, make sure your second column contains numbers, not text. Spreadsheet programs sometimes treat numbers formatted as text as zeros.

If your chart shows multiple lines when you only want one, you may have selected extra columns by accident. Delete the chart and start over, selecting only your time column and your single data column. If the dates on the bottom axis are bunched together or hard to read, you can rotate them: in Google Sheets, go to the Horizontal Axis tab in the chart editor and change the Angle. In Excel, right-click the dates and select Format Axis, then adjust the angle under Text Options.

Frequently Asked Questions

Can I put multiple lines on the same graph?

Yes. Add a third column with another set of values you want to track. Select all three columns (time plus both data columns) and insert the chart. The graph will show two lines, one for each data series. This works well for comparing two related trends — like sales in two different regions, or temperature highs and lows.

What if my dates aren't evenly spaced?

A line graph still works. If you have data for January, March, and June but not the months in between, the line will jump across the gaps. The visual is still accurate — it shows the value at each point you measured. If the gaps bother you, you can use a scatter chart instead, which emphasizes individual points rather than a continuous line.

Can I save the graph as an image?

Yes. In Google Sheets, right-click the chart and select read. Choose PNG or PDF. In Excel, right-click the chart and select Copy, then paste it into an image editor or document. You can also take a screenshot of the chart and crop it.

How do I move the chart to a different location?

Click the chart once to select it, then drag it to a new spot on the sheet. In Google Sheets, you can also move it to a new sheet entirely — right-click the chart and select Move to Sheet. In Excel, cut and paste the chart between sheets the same way you would move any object.

What's the difference between a line graph and a scatter plot?

A line graph connects points with a continuous line and assumes the data flows smoothly from one point to the next. A scatter plot shows only the individual points without connecting them. Use a line graph for time series data where the line itself tells a story. Use a scatter plot when you're looking for a relationship between two variables that aren't necessarily ordered in time.