My files grew by one pixel when saving from psd to jpg

I agree with JJMack. I think you are doing some process (adding image or someone else) that resize the document. 

Thank you for all of your responses - but I have to tell you, I really am not changing the canvas size or anything along those lines,  This same exact thing has also happened to other members of the team.  

My process on this is as follows:

I have a pre-exisiting template our team created that I open in Photoshop.  I drag the image I want to resize into the template and size to fit.  When I think it looks good, I "Save As" and make sure the file weight is under 2m and save it as a jpeg.  This does not happen all the time - it happens very rarely.  But when it does, it is always by exactly one pixel.  I'm always using the same exact template and the size of the template never changes.  It's only the jpeg. This same thing has happened with other folks as well.  It's very strange and, since it is not consistent, I can't replicate it on demand.  At no point am I ever going into Canvas Size, not even by accident.  It's not part of my workflow and I can't see how I could even accidentally change that.  

What command you are using to save file? Export As, Save for Web or Save As? From where you are acessing save command? More details and perhaps some screenshot can help us to replicate the problem or to figure out what is wrong.

I agree with JJMack. Probably you have added something on the design that have changed the canvas size of the template.

Hi!

Are you dragging an image into your template, and then resizing it? What is your workflow when you process your images? And what version of Photoshop are you using?

Michelle

Actually that would be a 1920 Pixel canvas size change.  Template file should not be overridden unless you are modifying your templates design.  Template are not changed when you use them you save out new files.  Your template file should  not be change at all.  It should still have its 1920x1080px  with the content it has. If you are using a newer version of Photoshop you can change the .PSD extension to PSDT to protect you template from accidental modification.  Your PSDT template will open  as a new unsaved document with you template's layers and content.  You will not be able to accidentally overwrite your template. If your Photoshop opened template document canvas size changes when you populate it.  Something you did populating the template change the documents canvas size. Photoshop does nothing on its own. File size and canvas size are not the same.  File size depends on what the file formats support and how well the document data can be compressed image content plays a big roll there.  More image detail requires saving more data.