Today, I am going to show you how to change DPI in LXDE.
There is no need to change DPI in normal screens. But the screens with high resolution results in very small font size.
First of all find the right dpi for your resolution here.
Now create a file ~/.Xresources
sudo vim ~/.Xresources
And add the following content in it (Replace the DPI with your own)
! Xft settings-----------
Restart the LXDE
sudo service lightdm restart