How to resize artboard/canvas in Illustrator
To resize the Illustrator's canvasGo to File->Document Setup and click button on the pop up dialog.This will highlight all existing artboards. Use 8 knobs on the highlighted rectangle to adjust size of any artboard.
To change width and height to specific size please see How to change width and height of an artboard for alternative way of resizing the canvas using width/height input boxes, when you must use exact values.
Note that after CS3 there is no canvas in Illustrator, like there is in Photoshop. It has artboards.
By default a newly created file contains one artboard. But it is possible to add more artboards to the same .ai document. Each artboard can contain its own set of geometric shapes.
Step by step process to edit size of an artboard is visualized in images below.
|Step 1: Go to File menu and click Document Setup.|
|Step 2: Click button on the Document Setup dialog that was just opened.|
You will notice that it's on the modal Document Setup dialog under "General" tab which is already selected by default.
|Step 3: Use the 8 knobs to adjust the width, height or orientation of the artboard.|
Artboards Were Introduced To Illustrator After Version CS3
In CS3 and prior versions of Illustrator, to change the size and angle of orientation for the document area (you can call it canvas in earlier versions) you would simply use the Document Setup dialog box itself.
In versions superseding CS3, a new button was added to the Document Setup dialog called "Edit Artboards". This is where you go to change the size and orientation of any existing artboard.