To achieve a score of 5 on the AP Calculus BC exam, students typically need to be in the top 50% of test-takers, which historically corresponds to answering about 60% to 70% of questions correctly. The grading is not based on a fixed percentage but rather follows a bell curve, meaning that competition is significant. It's advised to aim for a high score rather than trying to determine a minimum threshold. The AP Calculus BC exam is considered one of the more generously graded AP tests, similar to AP Chinese Language and Culture, where a high percentage of students earn a score of 5. The distribution of scores varies by exam, with fewer students achieving a 5 in subjects like Physics B and US History. For the most accurate and updated statistics, resources from the College Board and Wikipedia are recommended.