**Trend analysis** is used to summarize the historical trend (or “pattern”) of data and forecast future values.

The following step-by-step example shows how to perform trend analysis in Excel.

**Step 1: Create the Data**

First, let’s create the following dataset in Excel that shows the total sales made by a company during 15 consecutive years:

**Step 2: Create a Scatter Plot**

Next, we will create a scatter plot to visualize the sales values over the years.

To do so, highlight the cell range **A2:B16**, then click the **Insert** tab along the top ribbon, then click the **Insert Scatter** icon in the **Charts** group:

The following scatter plot will appear:

The x-axis displays the years and the y-axis displays the sales for each year.

**Step 3: Add a Trendline**

Next, click anywhere on the scatter plot to make the chart active.

Then click the tiny green plus sign ( + ) in the top right corner of the chart and click the box next to **Trendline**:

In the **Format Trendline** panel that appears on the right side of the screen, select the button next to **Linear**, then check the box at the bottom next to **Display Equation on chart**:

A linear trendline along with a trendline equation will be displayed on the scatter plot:

**Step 4: Interpret the Trendline**

We can see that the trendline equation is:

y = 4.9071x + 136.21

This tells us that for each additional year, the expected total sales increases by **4.9071**.

Since this value is positive, it tells us that sales (on average) increase over time.

We can also use this equation to predict the total sales for a given year in the future, assuming the trend holds.

For example, we can plug in the value **20** for **x** in the trendline equation to predict what the sales will be in year 20 for this company:

- y = 4.9071x + 136.21
- sales = 4.9071(20) + 136.21
- sales = 234.352

Using this equation, we predict that the total sales in year 20 will be **234.253** units.

**Note**: We used a linear trendline for the trend analysis in this example, but you can add a more complex trendline by clicking a different option under **Trendline Options** within the **Format Trendline** panel.

**Additional Resources**

The following tutorials explain how to perform other common operations in Excel:

Excel: How to Add One Trendline for Multiple Series

Excel: How to Find Trendline Equation Without Chart

Excel: How to Find the Slope of a Trendline