IMDB (international movie database) has a parents' guide section for all movies and TV series.
It will list all sex, violence, drugs, swearing, fearful scenes etc allowing you to make an informed choice on any movie. ie a woman is seen from behind, part of her bare buttock is seen, a man is shot on screen but then cuts away quickly.
I like the specifics of it rather than a general overview rating of 15 or whatever.