The ACT is an achievement test, measuring what a student has learned in school. The SAT is more of an aptitude test, testing reasoning and verbal abilities. The ACT has up to 5 components: English, Mathematics, Reading, Science, and an optional Writing Test.

The required portion of the ACT is divided into four multiple choice subject tests: English, mathematics, reading, and science reasoning. Subject test scores range from 1 to 36; all scores are integers. The English, mathematics, and reading tests also have sub scores ranging from 1 to 18.