[10] The ACT test covers four academic skill areas: English, mathematics, reading, and scientific reasoning.

[11] The ACT was first introduced in November 1959 by University of Iowa professor Everett Franklin Lindquist as a competitor to the Scholastic Aptitude Test (SAT).

[12] The ACT originally consisted of four tests: English, Mathematics, Social Studies, and Natural Sciences.

[19] To develop the test, ACT incorporates the objectives for instruction from middle and high schools throughout the United States, reviews approved textbooks for subjects taught in Grades 7–12, and surveys educators on which knowledge skills are relevant to success in postsecondary education.

ACT publishes a technical manual that summarizes studies conducted on its validity in predicting freshman GPA, equating different high school GPAs, and measuring educational achievement.

[20] Colleges use the ACT and the SAT because there are substantial differences in funding, curricula, grading, and difficulty among U.S. secondary schools due to American federalism, local control, the prevalence of private, distance, homeschooled students, and lack of a rigorous college entrance examination system similar those used in some other countries.

ACT scores are used to supplement the secondary school record and help admission officers put local data—such as coursework, grades, and class rank—in a national perspective.

[21][citation needed] The majority of colleges do not indicate a preference for the SAT or ACT exams and accept both, being treated equally by most admissions officers.

While the exact manner in which ACT scores will help to determine admission of a student at American institutions of higher learning is generally a matter decided by the individual institution, some foreign countries have made ACT (and SAT) scores a legal criterion in deciding whether holders of American high school diplomas will be admitted at their public universities.

The ACT is more widely used in the Midwestern, Rocky Mountain, and Southern United States, whereas the SAT is more popular on the East and West coasts.

The required portion of the ACT is divided into four multiple-choice subject tests: English, mathematics, reading, and science reasoning.

The calculator requirements are stricter than the SAT's in that computer algebra systems (such as the TI-89) are not allowed; however, the ACT permits calculators with paper tapes, that make noise (but must be disabled), or that have power cords with certain "modifications" (i.e., disabling the mentioned features), which the SAT does not allow.

The passages are representative of the levels and kinds of text commonly encountered in first-year college curriculum.

Specifically, questions will ask students to use referring and reasoning skills to determine main ideas; locate and interpret significant details; understand sequences of events; make comparisons; comprehend cause-effect relationships; determine the meaning of context-dependent words, phrases, and statements; draw generalizations; and analyze the author's or narrator's voice and method.

[35] The science section was mandatory until 2024, when it was made optional with the goal of giving students additional flexibility when taking the ACT exam.

Two trained readers assign each essay subscores between 1 and 6 in four different categories: Ideas and Analysis, Development and Support, Organization, Language Use and Conventions.

The chart below summarizes each section and the average test score based on graduating high school seniors in 2024.

They caution that "because admission policies vary across colleges, the score ranges should be considered rough guidelines."

[44] The ACT is offered seven times a year in the United States and its territories, Puerto Rico, and Canada: in September, October, December, February, April, June, and July.

In other locations, the ACT is offered five times a year: in September, October, December, April, and June.

The ACT is generally regarded as being composed of somewhat easier questions versus the SAT[51][citation needed], but the shorter time allotted to complete each section increases difficulty.

[56][failed verification] (Concordance data for ACT scores less than 11 is not yet available for the current version of the SAT.)