How to Add a Trendline in Excel Using the Built-in Trendline FeatureĮxcel also has a built-in trendline feature that can be used to add a trendline to a data set. Plugging these values into the trendline equation, we get: You can calculate the slope and y-intercept using the following equations: x = the independent variable (the variable that you are using to predict the dependent variable).y = the dependent variable (the variable that you are trying to predict).Once you have these values, you can use the following equation: To do this, youll need to know the x-values and y-values of your data set. Then, youll need to calculate the trendline equation yourself. First, youll need to select the data set that you want to add the trendline to. How to Add a Trendline in Excel ManuallyĪdding a trendline in Excel manually is a simple process. In this article, well show you how to add a trendline in Excel step-by-step. In Excel, you can add a trendline to a data set either manually or using the built-in trendline feature. They are often used in financial analysis to predict future events. A trendline is a line drawn on a graph to show the general direction that a data set is moving.