Screenplay formatting is one of the important part in Screenplay writing. Because you need show your script to producer, actor, actress and other persons to make your movie. Also your film script must be written in world most standard screenplay format.
If you want to write your screenplay with formatted way, first choose good screenplay writing software. Screenwriting software provide options to align your screenplay.but you need to learn some screenplay formatting guides.
Basic screenplay Format
Each scene must contain character (who), situation (what), time of day (when), purpose of action (why) and place of action (where). Screenplay must be written in present tense.
Font : Use Courier/Courier Final Drat font.
Page Margins : 1″ Top; 1″ Bottom
Scene Heading (Also called slug line) : All Caps, 1.5″ Left
INTERIOR or EXTERIOR (for interior scene start with slug line INT, for exterior scence start with slug line EXT, for both use INT/EXT)
Description of location (Location is set at the beginning of every scene)
Time of day (DAY, DAWN, DUSK and NIGHT)
Avoid statements such as moments later, earlier,in five minutes because we cannot see this moments visually.
Action Margins : 1.5″ Left; 1″ Right
Character Names : All caps,3.5″ from left
Parenthetical Margins: 3″ from left
Dialogue Columns: 2.5″ Left; 2.25″ Right
Transition Margins : All caps,1.5″ from right
Use paragraph breaks
Character is introduced
Subject is established
Visual is presented
Capitalization for emphasis is really important.
1 page of script is equal to 1 minute. So if you create 180 minutes movie screenplay than your screenplay have 181 pages (1 page for title card).
Read this sample screenplay format with guide : link