How to: Resize/scale an image to fit specific dimensions in Photoshop (for example, for a poster)

This guide outlines how one could go about scaling an image to fit certain dimensions. For example, if you want to create a 10x20-inch poster, you would need to scale the source image appropriately. This guide will outline how to do that in Photoshop. 

If you do not have a valid Photoshop license:

  1. The SCI128 and LIB106 computer labs at UBC Okanagan have iMacs with Photoshop installed. 
  2. Log into these computers with your CWL.stu as the username and your CWL password.
  3. Open Launchpad and open Photoshop (or hit Command+Spacebar and type "Photoshop" and then enter)
  4. When it asks you to sign in, enter just "", which should take you to a CWL portal called UBC Student Adobe, where you will sign in with your credentials
  5. Note: Sometimes, it will say Photoshop encountered an error. Just try quitting Photoshop and relaunching it. This typically resolves that.


To scale an image to fit your desired dimensions:

  1. Open Photoshop
  2. Click "Open" and select the image you want to scale.
  3. Click on the Image tab, and select Image Size
  4. In this window, you can specify what you want the image size to be. Under the "Fit To:" option, you can select some presets or just select Custom
  5. You will notice that there is a link icon between the height and the width. When this option is selected, the image will retain the original aspect ratio of the image (i.e., the height and width of the image will scale proportionately) . Select this if you want to keep the proportions, but typically you will have to uncheck this as the aspect ratio of what you're trying to create is different than the original image.
  6. You will notice a setting called "Resolution." This will affect the quality of the image (higher resolution = more pixels per inch = "better quality"). The industry standard for quality images is 300 dpi, but you can play with it and choose what you want. Do note the "Image Size" label at the top, which will tell you how much space this image will take up. Bigger images and higher resolutions will increase the file size.
  7. Your image should now be scaled to the dimensions you want, and you can confirm this by looking at the bottom left of the page where it lists the dimensions. 
  8. To save this image as a picture, click the File tab and then Export, and then you can Quick Export as PNG or click Export As... to customize the file.

Alternatively, you can:

  1. Click New and create a new canvas with the dimensions you want the final image to be
  2. Drag and drop the original image into this canvas and fit it how you want it. 


If you aren't able to get it working, please contact the Student Support Analyst at

Posted by: - Tue, Mar 14, 2023 at 11:39 AM. This article has been viewed 3858 times.
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