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 subscores ranging from 1 to 18 (the subject score is not the sum of the subscores). In addition, students taking the optional writing test receive a writing score ranging from 2 to 12 (this is a change from the previous 1–36 score range); the writing score does not affect the composite score. The ACT has eliminated the combined English/writing score and has added two new combined scores: ELA (an average of the English, Reading, and Writing scores) and STEM (an average of the Math and Science scores).These changes for the writing, ELA, and STEM scores were effective starting with the September 2015 test.

Each question answered correctly is worth one raw point, and there is no penalty for marking incorrect answers on the multiple-choice parts of the test; a student can answer all questions without a decrease in their score due to incorrect answers. This is parallel to several AP Tests eliminating the penalties for incorrect answers. To improve the result, students can retake the test: 55% of students who retake the ACT improve their scores, 22% score the same, and 23% see their scores decrease.

The first section is the 45-minute English test covering usage/mechanics, sentence structure, and rhetorical skills. The 75-question test consists of five passages with various sections underlined on one side of the page and options to correct the underlined portions on the other side of the page. Specifically, questions focus on usage and mechanics – issues such as commas, apostrophes, (misplaced/dangling) modifiers, colons, and fragments and run-ons – as well as on rhetorical skills – style (clarity and brevity), strategy, transitions, and organization (sentences in a paragraph and paragraphs in a passage) – and sentence structure – constructing sentences in a stylistically and grammatically correct manner.

The second section is a 60-minute, 60-question math test with the usual distribution of questions being approximately 14 covering pre-algebra, 10 elementary algebra, 9 intermediate algebra, 14 plane geometry, 9 coordinate geometry, and 4 elementary trigonometry questions.However, the distribution of question topics varies from test to test. The difficulty of questions usually increases as you get to higher question numbers. Calculators are permitted in this section only. 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.[29] Standard graphing calculators, such as the TI-83 and TI-84, are allowed. Within the TI-Nspire family, the standard and CX versions are allowed while the CX CAS is not. This is the only section that has five answer choices per question instead of four.

The reading section is a 35-minute, 40-question test that consists of four sections, three of which contain one long prose passage and second one contains two shorter prose passages. The passages are representative of the levels and kinds of text commonly encountered in first-year college curriculum. This reading test assesses skills in three general categories: key ideas and details, craft and structure, and integration of knowledge and ideas. Test questions will usually ask students to derive meaning from texts referring to what is explicitly stated or by reasoning to determine implicit meanings. Specifically, questions will ask you 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.

The science test is a 35-minute, 40-question test. There are seven passages each followed by five to seven questions. The passages have three different formats: Data Representation, Research Summary, and Conflicting Viewpoints. While the format used to be very predictable (i.e. there were always three Data Representation passages with 5 questions following each, 3 Research Summary passages with six questions each, and one Conflicting Viewpoints passage with 7 questions),[31] when the number of passages was reduced from 7 to 6, more variability in the number of each passage type started to appear. But so far, there is still always only one Conflicting Viewpoints passage. These changes are very recent, and the only reference to them so far is in the recently released practice test on the ACT website.

The optional writing section, which is always administered at the end of the test, is 40 minutes (increasing from the original 30-minute time limit on the September 2015 test). While no particular essay structure is required, the essays must be in response to a given prompt; the prompts are about broad social issues (changing from the old prompts which were directly applicable to teenagers), and students must analyze three different perspectives given and show how their opinion relates to these perspectives. The essay does not affect the composite score or the English section score; it is only given as a separate writing score and is included in the ELA score. 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. Scores of 0 are reserved for essays that are blank, off-topic, non-English, not written with a no. 2 pencil, or considered illegible after several attempts at reading. The subscores from the two different readers are summed to produce final domain scores from 2 to 12 (or 0) in each of the four categories. If the two readers’ subscores differ by more than one point, then a senior third reader makes the final decision on the score. The four domain scores are combined through a process that has not been described to create a writing section score between 1 and 36. Note that the domain scores are not added to create the writing section score.

Although the writing section is optional, many colleges require an essay score and will factor it into the admissions decision (but fewer than half of all colleges have this requirement).