ACT Science: a complete guide to the format, the optional section, the scoring, the reporting categories, and who should take it

Why the format of ACT Science is worth real points

ACT Science changed in 2025, and the change is the first thing to get right, because it decides whether you take the section at all and how you read every passage. This guide ties together the matching dot-point pages, each with its own practice: the format and the optional section, what ACT Science actually tests, the three reporting categories, how ACT Science is scored, and who should take ACT Science.

The enhanced ACT made Science optional

In 2025, ACT, Inc. introduced the enhanced ACT, and two sections became optional: the long-standing Writing test and now Science. The core of the test, the part that produces the Composite, is now English, Math, and Reading only.

Science did not vanish. When you take it:

• You receive a Science section score on the 1 to 36 scale.
• That score is combined with Math into a STEM score.
• Science is not averaged into your Composite.

The legacy ("classic") ACT, where Science was one of four sections in the Composite, was offered through late 2025 before being retired, with the enhanced paper test rolling out from September 2025.

Structure: 40 questions, several passages

ACT Science is 40 questions grouped under several short passages, almost all paired with figures: line graphs, bar charts, data tables, and diagrams.

• Enhanced ACT: 40 questions in 40 minutes (about one minute per question).
• Legacy ACT: 40 questions in 35 minutes.
• No calculator is needed; the arithmetic is light and the data are on the page.
• Content is drawn from biology, chemistry, physics, and Earth and space science, but no advanced knowledge is required.

Each passage uses one of three formats, covered in depth in the pacing and the three passage types module: Data Representation (graphs and tables), Research Summaries (experiments), and Conflicting Viewpoints (competing explanations).

What it really tests: reasoning, not recall

The defining feature of ACT Science is that it measures science reasoning, not memorised content. The three skills are:

• Interpreting data: reading values and trends from graphs and tables.
• Understanding experiments: variables, controls, and design.
• Evaluating conclusions: judging what the evidence supports.

Because the evidence is provided, you can score on a passage about a topic you have never studied. Only a handful of questions per test lean on basic background knowledge.

Scoring: 1 to 36, no penalty, feeding the STEM score

Your raw score is the number of correct answers out of 40, converted to a scale score from 1 to 36 by the form's conversion table.

On the enhanced ACT, Science is reported separately, combined with Math into the STEM score, and excluded from the Composite. You also get reporting-category subscores for the three skill areas.

The three reporting categories

Every question is sorted into one of three categories, reported as subscores:

• Interpretation of Data (the largest): reading values and trends from figures.
• Scientific Investigation: experimental tools, procedures, controls, and variables.
• Evaluation of Models, Inferences, and Experimental Results: judging whether a claim is supported.

Classifying a question by category tells you whether to read a figure, analyse a design, or weigh evidence.

Deciding whether to take Science

Because Science is optional, the decision depends on your goals and your targets.

1. Do any target programs require or recommend a Science or STEM score? If yes, take it.
2. Are you STEM-bound? If yes, take it, because Science feeds the STEM score those programs value.
3. Is Science a strength? If yes, it adds a flattering score with no Composite risk.
4. None of the above and time is tight? Skipping is reasonable, but the downside is low, so when unsure, take it.

How the format is examined

• Status. Optional on the enhanced ACT; scored 1 to 36; feeds the STEM score, not the Composite.
• Structure. 40 questions under several passages; 40 minutes (enhanced) or 35 minutes (legacy).
• Skill. Reasoning, not recall; almost every answer is on the page.
• Scoring. Raw count of correct answers, no penalty for wrong answers, reporting-category subscores.

Check your knowledge

A quick check on the format facts that drive your plan. Answer them, then read the solutions.

1. On the enhanced ACT, which three sections make up the Composite, and where does Science go instead? (2 points)
2. How many questions and minutes are in the enhanced ACT Science section, and what pace does that imply? (2 points)
3. A student leaves three Science questions blank to "play it safe." Why was that a mistake? (2 points)
4. Name the three reporting categories and the core skill of the largest one. (3 points)
5. Give two reasons a student should take the optional Science section. (2 points)