Photoshop not showing the real size of the images

Hello,

So, everytime that I open an image in Photoshop it shows me a reduced version of it.

I saved an 500px X 500px photo in Lightroom, but when I open it in Photoshop and compare to the real size of the photo, it shows a smaller size.

This picture shows the size difference, it's 100% in photoshop and in the mac viewer:

I just noticed this error when I was creating a friend's logo and noticed that, when I saved the image, the size was way bigger than when I saw it in Photoshop.

I always open a "Default Photoshop Size", create what I want to and cut the part that I want to save.

Here are the settings that I used (the default one):

And, after creating and cutting just the part that I want, here's the difference in sizing. And, especially in this exemple, it drives me crazy, because I have to know the real size of the header!

Has anyone ever had this problem? I have already reseted all settings, uninstalled and reinstalled the app, but it keeps happening.

Thank you in advance.