Although Sixteen Candles is rated PG, we imagine it would be rated PG-13 if it were made after that rating came out. (It actually came out a few months later that year.)
Sixteen Candles is chock-full of bad language, the kind of which, let's be real, thirteen-year-olds use all the time. Plus, there's a brief topless scenes as Sam jealously looks at Caroline's body in the shower.
In case you needed a reminder that this film, despite featuring a sympathetic female lead, was directed a man, the fact that he shows someone who's supposed to be a teenager showing like she's in a soft-core Playboy video proves it.