I've found it frustrating at times when I needed CMD in fullscreen for better visibility of the information displayed, but was not able to put it in fullscreen. If you didn't know, when clicking the "maximize" button, the CMD window only maximizes vertically, not horizontaly. After playing around with CMD, I have found a way to put it in fullscreen.
Step 1: Take Note of the Resolution of Your Screen
In the control panel, go to display, then click on resolution. There, you can see the resolution of your display. Take note of the width. For me, it is 1366.
Step 2: Open the Properties Tab
Open CMD, and then right-click on the frame (the orange part in the picture, not the black) and select properties.
Step 3: Calculate the Screen Buffer Size
In the properties window, go to the font tab and take note of the font width, generally 8. Now, take your screen width and divide it by 8. For me 1366÷8=170.75. If you get a decimal number, just round it up, so 171 in my case.
Step 4: Fullscreen
Now click on OK and maximize the window. It will now take up your whole screen.