If your OnePager project view is too wide, narrow, tall, or short when you export or print it, you probably need to change your aspect (width:height) ratio. You can do this in one of two ways:
Drag to Resize
First, zoom out so there is blank gray space surrounding your project view. To zoom out, go to the View tab and click the Zoom buttons.
Second, drag the edges of your project view up, down, left, right, or diagonally to resize the project view, just like you would a box or image in PowerPoint:
Go to Home > Project View Properties > Page Layout.
Adjust the Document width and Document height settings at the top of the form. You can also change the standard height of every row to be larger or smaller, which will also change your document height. For U.S. customers, these numbers are measured by default in inches. When possible, we recommend your width be approximately 62% larger than your height; read our blog post on why.
Click OK or Apply to see the new dimensions.