How to Make a Line Graph in Excel with 2 Variables

Creating a line graph in Excel with two variables is one of the best ways to see how two different sets of data relate to each other over time. Instead of looking at rows of numbers, you get a clear visual story that can instantly show you trends, comparisons, and relationships. This guide will walk you through exactly how to build, customize, and even level-up a two-variable line graph in Excel, step by step.

What Exactly is a Line Graph with Two Variables?

A line graph with two variables (also known as a multi-series line chart) plots two separate data series on the same chart. Each data series is represented by its own line, making it incredibly easy to compare their performance against each other and over the same period.

This is incredibly useful for answering business questions like:

• How did sales of Product A compare to Product B last year?
• Is our marketing spend leading to a corresponding increase in website traffic?
• Are paid search conversions growing faster than organic search conversions?

By plotting both variables on one graph, you can spot correlations and patterns an ordinary table of data would hide.

Setting Up Your Data Correctly in Excel

Before you even think about charts, your data needs to be organized properly. This is the most important step, and getting it right makes the rest of the process a breeze. A clean data source is the foundation of a clear graph.

Arrange your data in columns. Your first column should be your independent variable - typically a time period like days, months, or years. The next two columns should contain your two dependent variables - the metrics you want to measure and compare.

Here’s a perfect example structure for tracking monthly revenue from two different services:

Example Data Structure:

Tips for Data Preparation:

• Keep it Clean: Make sure your column headers are short and descriptive. They’ll be used to create the chart legend automatically.
• Consistent Formatting: Ensure your numbers are formatted as currency or general numbers, and your dates are formatted as dates. Inconsistent formats can cause Excel to misinterpret the data.
• No Empty Rows or Columns: Have your data in a single, contiguous block. Gaps can confuse Excel when it tries to select the data range for your chart.

Step-by-Step: How to Create the Two-Variable Line Graph

Once your data is neatly arranged, creating the graph itself takes just a few clicks. Follow these steps:

Step 1: Select Your Data

Click and drag your mouse to highlight the entire dataset, including the headers in the first row. In our example above, you would select cells A1 through C7.

Step 2: Insert the Line Chart

With your data selected, navigate to the Insert tab on Excel’s top ribbon. In the Charts group, find the icon that looks like a small line graph and click it. It’s officially called "Insert Line or Area Chart."

Step 3: Choose Your Chart Type

A dropdown menu will appear showing several line chart options. For comparing two variables, the best choice is usually Line with Markers. The markers (dots, squares, etc.) on each data point make it easier to pinpoint exact values along the trendline. Click this option.

And that's it! Excel will immediately generate a line graph with an X-axis (your months), a Y-axis (your revenue values), and two distinct lines representing Service A and Service B. Now, it's time to make it look professional.

Customizing Your Graph for Clarity and Impact

An unedited Excel chart works, but a well-customized chart communicates information effectively. Here’s how to polish your new graph.

Add a Descriptive Chart Title

Your chart needs a title that tells the viewer exactly what they're looking at. Click on "Chart Title" at the top of an auto-generated chart and type something more descriptive, such as "Monthly Revenue Comparison: Service A vs. Service B".

Label Your Axes

Without axis labels, the numbers are meaningless. To add them, click on your chart to bring up the Chart Design tab. On the very left, click Add Chart Element > Axis Titles and add both a "Primary Horizontal" and "Primary Vertical" title. Label the horizontal X-axis "Month" and the vertical Y-axis "Revenue ($)."

Adjust Colors and Line Styles

You can change the color and style of each line to make them easier to distinguish or to match your company's branding.

• Right-click on one of the lines in your chart.
• Select Format Data Series... from the dropdown menu.
• A pane will open on the right. Click the paint bucket icon (Fill & Line).
• From here, you can change the Color, Width, Dash type, and even the appearance of the Markers. Repeat for the second line.

Refine the Legend

Excel creates a legend automatically from your column headers. You can click on it and drag it to a better position (Top, Left, Bottom, etc.) that doesn’t interfere with the data visualization.

Pro Tip: Handling Variables with Different Scales

What happens if one variable is in the tens of thousands (like 'Ad Impressions') and the other is a small percentage (like 'Click-Through Rate')? If you plot them on the same axis, the percentage line will look completely flat and useless against the large numbers.

The solution is to add a secondary axis. This creates a second Y-axis on the right side of the chart scaled specifically for your second variable.

How to Create a Secondary Axis in Excel

1. Create the initial two-variable line graph just as we did before.
2. Right-click on the data line that needs its own scale (the one that looks flat).
3. Select Format Data Series...
4. In the format pane that appears, under Series Options, select the Secondary Axis radio button.

Instantly, a new axis will appear on the right side of your chart, and the selected line will be rescaled against it. Now both trendlines are clearly visible!

Turning it into a Combination Chart

To make a dual-axis chart even more readable, you can change one of the line graphs into a bar graph. This is known as a combination chart.

1. Right-click the line you moved to the secondary axis.
2. Select Change Series Chart Type...
3. A new window will open showing both of your data series. For the series on the secondary axis, use the dropdown to change its chart type from 'Line' to 'Clustered Column'.
4. Click OK.

You now have a highly professional chart showing one variable as a line and the other as columns, each perfectly scaled to its own axis. This is perfect for visualizing cause-and-effect relationships, like ad spend (columns) vs. website conversions (line).

Final Thoughts

Mastering the two-variable line graph in Excel elevates your reports from simple data tables to compelling visual stories. Whether you're tracking sales, monitoring marketing campaigns, or analyzing operational data, this skill helps you uncover insights and communicate performance with immediate clarity. Once you get the hang of it, you'll find yourself turning to this versatile chart type again and again.

While Excel is a powerful tool, manually exporting data, cleaning spreadsheets, and building the same reports week after week can quickly eat up valuable time. This is especially true when your data lives in different places like Shopify, Google Analytics, and Facebook Ads. At Graphed, we automate all of that. You simply connect your data sources once, and then you can ask for charts and dashboards in plain English. Instead of clicking through menus in Excel, you can just ask, "Show me a line graph comparing revenue from Product A and Product B for the last quarter," and we build the real-time visualization for you instantly.