There is no limit on pixel size for image upload on a contacts profile. 

Please click here to see how to upload an image to a contacts record. 

If you experience any issue with uploading an image to a contacts profile then It could be corrupt image causing an issue.  

We can either test the image for you or if you want you can re-scale the image in Microsoft paint etc and then try again.

Please contact our Support Helpdesk if you need any assistance.