Setting tty resolution via fbset(8)
fbset is a great tool to set tty resolution, especially if setting it through grub doesn’t work for you.
The package itself is available in Arch repositories, or if you want to download it from upstream: http://users.telenet.be/geertu/Linux/fbdev/fbset-2.1.tar.gz
The two important options for setting resolution are:
-xres <value>
set visible horizontal resolution (in pixels)
-yres <value>
set visible vertical resolution (in pixels)
So for example executing fbset -xres 1920 -yres 1080 will set your tty resolution to 1920x1080
SIDE NOTE: in order for fbset to work without root permissions, your user has to be part of the video group