VIM Editor ::: Resizing Window Splits

To make splits in VIM editor wider:

<CTRL>-W + >

To make splits in VIM editor more narrow:

<CTRL>-W + <

To make splits in VIM editor more wide by 30 characters:

:30winc >

OR:

30 + <CTRL>-W + >

To make splits in VIM editor more narrow by 30 characters:

:30winc <

OR:

30 + <CTRL>-W + <

Source