Line spacing refers to the amount of space between lines. Although default line space in Google Docs is 1.15, many time authors need double space in Google docs.
Two Methods to add double space
Select the text that you need to double space and use any of the following methods. To select the entire document, you can use the “Ctrl + A” for Windows or “Command + A” for MacOS.
Method 1: Format Menu
Navigate to Format >Line spacing and select “Double”
Method 2: Tool Bar
Click on the Line spacing icon (as shown below) on Tool Bar and click “Double”