Here are some tips for interpreting ratings, with links to underlying analysis.
Average scores: Across all series the average score is around 64% (6.4 on a ten-point scale), except Metacritic critics which average 58%. Something around this level is thus close to average for our sample of around 9000 films.
Thresholds: As a rough guide across the different series, a rating over 70% (or 7.0) is very good, and over 80% (or 8.0) is outstanding. However high scores are much more common for Rotten Tomatoes critics. See Analysis.
High scores from Rotten Tomatoes: Rotten Tomatoes critics’ ratings are calculated as a percentage of positive reviews. This means that very high scores are quite common for critically well received films, with one in five films scoring 90% or more. This is not true of other series, so adjust accordingly.
Ratings are by critics and film fans, not the general public: The people enter ratings on websites are a self-selecting group – “film fans” – that has tastes quite close to critics, although some differences remain. The wider public has quite different tastes from critics and film fans. There is only a weak relationship between what these groups and audiences like, as measured by audience research, and almost none at all with box office. See Analysis.
“Classics” tend to well: Established classics do very well, often better than more recent films. Few want to down vote esteemed films. Keep this in mind if comparing films from different eras.
Animated films often score very well. They may still not be for you.