How To Add a Trendline in Excel Charts in 2024

Microsoft Excel is a popular and powerful data visualization and analysis software program that provides many key functions and tools. One is the ability to add a trendline to your charts.

In our data-driven world, decisions, predictions, and forecasts need to be backed by supporting evidence and figures. Understanding your company’s data and knowing how to use it to help you make informed decisions is crucial. Trendlines can be an invaluable tool to help interpret data and add meaning to your findings.

This article will discuss what a trendline is and how you can add it to your Excel charts. Going a step further, learning to add multiple trendlines to the same chart can help with data interpretation. We’ll also take a look at the different Excel chart types that can become more meaningful through the use of trendlines.

More specifically, we cover:

• Step 1. Select the chart
• Step 2. Click the Chart Design tab
• Step 3. Click Add Chart Element
• Step 4. Select Trendline
• Step 5. Select the type of trendline
• How to add multiple trendlines in the same chart
• What is a trendline?
• Excel chart types for trendlines
• Why and when you should use trendlines
• Common reasons why you can’t make a trendline
• The Excel trendline formula

Step 1. Select the chart

Select the chart you want to add a trendline to by clicking on it.

Step 2. Click the Chart Design tab

Once you’ve clicked on the chart, click on the Chart Design tab. If you have a Windows computer, click on the + at the top right of your chart.

For Mac:

For Windows:

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Step 3. Click Add Chart Element

For Mac, select Add Chart Element. For Windows, you’ll see the option to add a trendline to your chart after clicking on the +.

For Windows:

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Step 4. Select Trendline

Select the option to insert a trendline. This will open a drop-down list of different types of trendlines available to you.

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Step 5. Select the type of trendline

Select the type of trendline you want to add to your chart. You can also click on More Trendline Options if you don’t see the specific trendline you want to add. This will open up the Format Trendline pane with all available trendline options.

Select the checkbox of the type of trendline you want to add.

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You have now successfully added a trendline to your chart.

How to add multiple trendlines in the same chart

You can add more than one trendline to your chart. You can either add a trendline for each data series or insert different trendline types for the same data series.

Add a trendline for different data series

If you have two different data series in the same chart, you can add a trendline to each. For example, let’s say you have a chart that depicts both the average monthly high and low temperatures for Texas.

Follow the steps listed for adding a trendline to a single data series and repeat for each additional data series.

Select one data series at a time. For this example, we’ll first add a trendline for the average high temperature data series, then repeat the steps to insert a trendline for the average low temperature data series.

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The finished result will have a trendline for both of the data series.

Add different types of trendlines for the same data series

Adding different types of trendlines for the same data series is as simple as repeating the steps for adding a single trendline.

1. Click on your graph.
2. Go to the Chart Design tab.
3. Select Add Chart Element.
4. Select Trendline.
5. Click on the type of trendline you want to add.

Let’s use our example dataset that shows the average monthly temperatures of Texas again. We added a polynomial trendline the first time, so let’s add an exponential trendline.

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What is a trendline?

A graph trendline (otherwise known as a line of best fit) is a visual representation of the data’s best fit using a line or curve. It helps illustrate the trend in a data series and is commonly used to determine patterns or make predictions.

A trendline can serve as a powerful data visualization tool that reveals the overall direction of your data—helping your business make more accurate forecasts about future patterns.

Trendlines can give valuable insight into the relationship between your data. A positive slope in the trendline indicates that your data has a positive correlation. Alternatively, a negative slope in the trendline suggests a negative correlation.

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No trend means there’s no correlation between your data. In the case of a scatterplot chart, randomly scattered data points showing no pattern are an example of data with no trend since there’s no correlation between the x-axis and the y-axis.

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Excel chart types for trendlines

Trendlines aren’t available for all chart types. Changing a chart type to one that doesn’t support trendlines can remove the trendline.

Chart types that support trend lines include:

• Line
• Column
• Stock
• Bubble
• XY scatter
• Area
• Bar chart

However, the following chart types don’t support trendlines:

• Radar
• Pie
• 3D
• Stacked
• Surface
• Doughnut chart

There are six types of trends or regression types. The type of trendline needed will depend on your data. You should choose the trendline that is the most meaningful for your data.

The types of trendlines available are:

• Exponential
• Linear
• Logarithmic
• Polynomial
• Power
• Moving average

Exponential

Use an exponential trendline whenever your dataset rises or falls at increasingly higher or lower rates. For example, a graph showing the value of an investment with compounding interest can use an exponential trendline to illustrate the effect of the compounding interest on the investment over time.

The value of your investment will rise at a constantly increasing rate. An exponential trendline is a curved line; therefore, you can’t use it if your dataset contains any negative or zero values.

Linear

A linear trendline refers to the best-fit straight line in your dataset. This type of trendline indicates that a dataset is increasing or decreasing at a steady rate, and the data points in the graph resemble a line.

Logarithmic

A logarithmic trendline is best for datasets that quickly increase or decrease and then level out. It refers to the best-fit curved line in the dataset, and you can use it for both positive and negative datasets.

Polynomial

Polynomial means “made up of several items.” A polynomial trendline appears as a curved line and is most useful when the data in your dataset fluctuates. A polynomial curve determines the number of fluctuations in your data by counting the number of “hills and valleys” that appear in the curve.

Power

A power trendline—just like an exponential trendline—can’t be used if your dataset contains any zero or negative values. It’s a curved line used on datasets that increase at a specific rate.

Moving average

A moving average trendline clearly shows a trend or pattern in the dataset by smoothing out fluctuations in the data. It takes the average of a specific number of data points and uses that average value as a point in the trendline. It determines the second point in the trendline by taking the average of the next set of data points.

Why and when you should use trendlines

Here are a few example situations where trendlines can be helpful:

• Measuring sales or revenue. When you add trendlines to compare sales between different periods of time (such as months or quarters), you can evaluate your current trends and make informed decisions about the future.
• Evaluating the stock market. Using a trendline, you can analyze stock price movements, see long-term trends, and consider potential exit points.
• Population growth. By looking back at past population changes, you can more easily make predictions about future growth.
• Website analytics. How much traffic are you attracting to your site? With trendlines, it’s easier to measure your current performance and identify future areas for improvement.

This list is not exhaustive, and there are many instances where trendlines can be useful.

Common reasons why you can’t make a trendline

If you run into issues while trying to make a trendline, you may be facing one of the following issues:

• Not enough data. If you don’t have enough data points to establish a pattern, Excel may not be able to create a trendline for you.
• Improper formatting. Your data must be organized with points on both the X-axis and the Y-axis in order to produce a trendline. Your graph also needs to be a scatter chart and not a line chart or a bar graph.
• Non-numeric data. If you have data on a graph that isn’t in numeric form, Excel won’t be able to generate a trendline.
• Incorrect selection. If you accidentally included additional rows or columns when making your initial selection, you could run into issues.

If you’re still having trouble creating a trendline after reviewing each of these steps, you may try searching through Microsoft’s Answers to receive help from Microsoft’s support community. You may also consider working through an Excel tutorial if you’re a beginner without much prior experience.

The Excel trendline formula

When you’re working in Excel, the most common type of trendline is a linear trendline. A linear trendline is represented as a straight line that best fits the corresponding data. Typically, the formula for this type of trendline equation is represented as y = mx + b, commonly referred to as the slope-intercept formula.

Let’s take a quick look at the meaning of each variable:

• y represents the dependent variable (usually on the vertical axis)
• x represents the independent variable (usually on the horizontal axis)
• m represents the slope of the line, indicating the rate of change between y and x
• b represents the y-intercept, the point where the line intersects the y-axis

When developing a trendline, Excel calculates the values of m and b based on points from your chart. The goal is to minimize the overall distance between the data points and the trendline.

However, different types of trendlines will have different formula structures to represent each one’s respective curves. The line will look different when you’re working with exponential, logarithmic, and polynomial equations. Excel is equipped to handle several different types of trendlines, although the linear formula above is the most commonly used.

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