Director Zack Snyder's much-anticipated movie - starring Ben Affleck as Batman, Henry Cavill as Superman and Gal Gadot as Wonder Woman - was handed the age classification due to "its intense sequences of violence and action throughout, and some sensuality", reported Entertainment Weekly.
Most superhero movies released these days adhere to the PG-13 rating, including Christopher Nolan's Dark Knight films, as do major blockbusters like "The Hunger Games" and "Fast & Furious".
The director has also confirmed, however, that Ben Affleck's Caped Crusader will get more screentime than Henry Cavill's Superman.
"Batman v Superman: Dawn of Justice" is released on March 26, 2016.