Data Analysis- How to Add a Line of Best Fit in Google Sheets

How to Add a Line of Best Fit in Google Sheets #

Google Sheets is a powerful tool for data analysis, and one useful feature it offers is the ability to add a line of best fit to a scatter plot. A line of best fit, also known as a trendline, helps visualize the general trend or relationship between two variables in a dataset.

Adding a line of best fit manually in Google Sheets involves a few simple steps:

  1. Open Google Sheets and create a new spreadsheet or open an existing one that contains the scatter plot data.

  2. Select the data range for which you want to add the line of best fit. Make sure the data includes both x and y values. For example, if you have x values in column A and y values in column B, select both columns.

  3. Click on the "Insert" menu and choose "Chart". This will open the Chart Editor on the right-hand side of the screen.

  4. In the Chart Editor, select the "Chart types" tab and choose "Scatter" from the list of options.

  5. Select the type of scatter chart that best represents your data. You can choose from options such as scatter chart, scatter chart with smooth lines, scatter chart with straight lines, etc.

  6. After selecting the chart type, go to the "Customize" tab in the Chart Editor. Under the "Series" section, you will find the "Trendline" dropdown menu.

  7. Click on the "Trendline" dropdown menu and select the type of trendline you want to add. Options include linear, polynomial, exponential, and many more.

  8. Once you select a trendline type, you will see the line of best fit added to your scatter plot. You can further customize the trendline by adjusting parameters like color, style, thickness, etc.

Adding a line of best fit using Google Apps Script is also possible. Here's an example of a simple script that adds a linear trendline to a scatter plot:

function addTrendline() {
var sheet = SpreadsheetApp.getActiveSpreadsheet().getActiveSheet();
var chart = sheet.newChart()
.setPosition(5, 5, 0, 0)

var trendline = chart.addTrendline(Charts.TrendlineType.LINEAR);


This script creates a new scatter chart using the data range 'A1:B10' and adds a linear trendline to it. The resulting chart is then inserted into the active sheet.

Use cases for adding a line of best fit in Google Sheets are numerous. Here are a few examples:

  1. Sales Analysis: Suppose you have data for monthly sales and want to identify the overall sales trend. Adding a trendline to a scatter plot of sales versus time can help visualize whether sales increase, decrease, or remain stable.

  2. Student Performance: If you have student test scores and want to examine the correlation between study time and scores, adding a trendline can reveal any relationship between these variables. This can be useful for analyzing the effectiveness of studying habits.

  3. Market Analysis: For businesses tracking market trends, adding a trendline to a scatter plot of sales or market share versus time can provide insights into long-term growth or decline. This information can guide decision-making and strategic planning. Adding a line of best fit in Google Sheets is a straightforward process that enhances data visualization and facilitates data analysis. Whether you do it manually or with the help of Google Apps Script, trendlines can provide valuable insights into the relationships between variables in your datasets.