In Illustrator, you can change the canvas size by using the Size property. To change the canvas size in Illustrator, follow these steps:

  1. In the File menu, choose New > File.
  2. In the New File dialog, enter a name for your new file and click OK.
  3. In the Graphics area of the new file, select a color and click OK.
  4. In the Properties area of your new file, set the following properties: Width (in pixels), Height (in pixels), and Canvas Size (in pixels). Click OK to close the file.