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The ACT Science section evaluates your scientific reasoning, data analysis, and critical thinking skills using science-based passages and questions. It's designed to see how well you can interpret information from graphs, experiments, and conflicting viewpoints – not how much biology or chemistry you've memorized.
In this guide, we'll break down everything you need to know about the ACT Science section: its format (including upcoming changes in 2025), the types of passages and questions you'll face, how it's scored, and key tips to help you succeed on test day.
The ACT Science section consists of 40 multiple-choice questions to be completed in 35 minutes. That gives you roughly 52 seconds per question, making time management a critical skill.
Those 40 questions are spread across 6 or 7 passages. Each passage presents some scientific information – it could be a data chart, an experiment summary, or a pair of conflicting theories – and is followed by about 5 to 7 questions related to that information.
The passages cover a mix of topics (biology, chemistry, physics, Earth/space science), and at least one passage will present opposing viewpoints on a scientific issue.
You're not allowed to use a calculator on the Science section (though the math required is minimal). All questions have four answer choices, and there is no penalty for guessing, so it's in your interest to answer every question.
Beginning with the April 2025 ACT (online format) and extending to all test formats by September 2025, the Science section will become optional for U.S. test takers. In the new format, students can choose whether or not to take the Science portion.
If you do take ACT Science under the enhanced format, the section will still feature 40 questions, but with a slightly longer time limit of 40 minutes. The content and structure of the questions remain the same – you'll still encounter passages with data, experiments, and viewpoints, and the skills tested do not change.
The major difference is how the Science score is used (more on scoring in a moment). Below is a summary comparing the current and new formats for ACT Science:
| ACT Science Section Aspect | Current ACT (before 2025 changes) | Enhanced ACT (2025 and onward) |
|---|---|---|
| Required or Optional? | Required (included as 1 of 4 sections) | Optional (student choice to take it or skip) |
| Number of Questions | 40 questions | 40 questions |
| Time Allotted | 35 minutes | 40 minutes |
| Passages | 6–7 passages (data, experiments, viewpoints) | Same types of passages (no content change) |
| Placement in Test | 4th section (after Reading) | Still offered as an additional section if chosen* |
| Contribution to Composite Score | Counts toward Composite (25% of composite) | Not included in Composite (reported as separate Science score) |
*In the enhanced format, if you opt in to Science, you will take it after the Reading section. If you opt out, your test will end with Reading (unless you're also taking Writing). State and school testing programs may decide whether to include Science for their students.*
As the table shows, the question count and types remain consistent, but the enhanced ACT gives you a bit more time per question and the option to skip the section entirely.
Importantly, starting in 2025 the ACT will classify English, Math, and Reading as the "core" sections used for the main score, while Science will be treated more like an add-on.
If you're taking the ACT in early 2025 or before, plan on doing the Science section as usual. If you're taking it in the later 2025 dates or beyond, you'll have a decision to make about whether to include Science in your testing plan.
The ACT Science section is essentially a open-book test where all the information needed to answer the questions is given in the passages. Each question refers to a specific piece of information from the passage – your job is to find it, interpret it, and use it to choose the correct answer. All questions are multiple-choice with four options (A, B, C, D), and they tend to be very concise (often just one sentence questions). Here are some key things expected of you on ACT Science questions:
Interpret Data from Figures: You'll frequently see graphs, tables, and charts. You might be asked to identify a trend, read a value, or extrapolate (predict beyond the given data) from a figure.
For example, a question might show a graph of plant growth over time and ask, "At what time did the plant reach 50 cm in height?" – you would locate 50 cm on the graph and find the corresponding time.
These questions test if you can recognize relationships in data and perform basic interpolations/extrapolations.
Understand Experiments: Many questions are based on descriptions of experiments. You'll need to understand the experimental setup, identify variables and controls, and interpret the results.
For instance, a passage might describe an experiment testing a new drug on bacteria with "Experiment 1" and "Experiment 2" having different conditions. A question could ask, "What was the purpose of Experiment 2?" – expecting you to realize it served as a control or tested a specific variable.
The test expects you to grasp the scientific investigation aspects: what's being tested, how it's being measured, and what conclusions can (or cannot) be drawn.
Analyze Conflicting Viewpoints: One passage will present two or more opposing theories or hypotheses about a scientific phenomenon. These are often text-heavy. You'll be asked to compare and contrast these viewpoints – for example, identifying a point of disagreement between two scientists, or determining what evidence would support one theory over the other.
A typical scenario: Scientist A and Scientist B propose different explanations for, say, why bees are disappearing. Questions may ask, "Which scientist would agree with the statement X?" or "How would Scientist B likely respond to a new study that found Y?"
You are expected to understand each viewpoint's premises and conclusions, and how they relate or conflict with each other. This tests higher-level critical thinking and reading comprehension skills using scientific content.
Overall, ACT Science questions expect you to use reasoning and evidence. Virtually every answer can be found or deduced from the passage information.
Not all ACT Science passages look the same. The test actually uses a few different formats to gauge your skills from different angles. Here are the three main types of passages you'll encounter, along with the skills they emphasize:
Data Representation: These passages are heavy on charts, graphs, and tables and light on text. They present data similar to what you might see in a science journal or lab report – for example, a table of chemical properties or a graph of an experiment's results. There is little narrative; you're mostly dealing with visual data.
Skills tested: You need to interpret and manipulate the given data – recognizing trends, reading values, and making inferences from the figures. You might have to translate information (e.g. turn a table into a graph mentally, or vice versa) and perform simple reasoning with numbers (no calculator, but the math is basic).
Example: A Data Representation passage might show three graphs of different species' population over time. Questions could ask which species had the greatest increase, or what the population was at a certain year, etc.
Data Representation items make up roughly 25–35% of the questions and are often considered the most straightforward because you can often find answers directly in the figures.
Research Summaries (Experiments): These passages describe one or more related experiments or studies in detail. They often have labels like "Experiment 1," "Experiment 2," etc., each outlining the procedure and results of a scientific test. Expect more text here as the passage explains the experimental setup, methods, and observations, usually alongside some data tables or graphs.
Skills tested: Understanding experimental design is key. You'll need to know how to identify hypotheses, independent and dependent variables, controls, and interpret the results of each experiment. Questions will often ask about why the researchers did something or what the results show. For example, "In Experiment 2, why did the scientists increase the temperature?" or "What conclusion can be drawn from the results of Experiment 1?"
You may also be asked to compare experiments – e.g. how Experiment 1 and 2 differ or what a similar result in both implies. Sometimes you'll need to predict an outcome if the experiment were changed slightly (testing your ability to extend the findings).
Research Summaries typically account for the largest portion of the test, about 45–60% of the questions (usually 3 passages). They require careful reading, but remember that all necessary info is given: even if you've never done that experiment in real life, the passage tells you what you need to know.
Conflicting Viewpoints: This passage type presents two or more different perspectives or hypotheses on the same phenomenon. Instead of experiments or data, you'll see short essays or statements by each viewpoint, often labeled as Scientist 1, Scientist 2, (and sometimes Scientist 3). There's usually minimal data or figures (maybe a simple diagram or none at all) – the emphasis is on the ideas and arguments.
Skills tested: Your task is to compare and evaluate the arguments. You must grasp each viewpoint's main idea and identify how the viewpoints relate: where they agree or disagree, what assumptions each makes, and what evidence each would support or refute. Questions might ask you to find a point of disagreement, determine which viewpoint a particular piece of evidence supports, or predict how one scientist would respond to the other's theory.
Example: A Conflicting Viewpoints passage might feature two paleontologists debating why dinosaurs went extinct – one blaming volcanic activity, the other an asteroid impact. A question could be, "Which statement about iridium layers would Scientist 1 most likely agree with?" requiring you to recall Scientist 1's stance and apply it.
These questions demand careful reading and critical thinking, similar to ACT Reading inference questions. Conflicting Viewpoints passages usually form 15–20% of the Science questions (generally just 1 passage on the test). Students often find this the most challenging passage type because it involves more reading and less straightforward "find the number in the chart" tasks. A useful strategy is to take brief notes on each viewpoint's position to keep track of who believes what.
Note: Every ACT Science section will contain a mix of these passage types. In the past, the test often had 7 passages (3 Data, 3 Research, 1 Conflicting). More recently, some forms use 6 passages (for example, 2 Data, 3 Research, 1 Conflicting) but still with 40 questions total. Either way, you'll see at least one of each type.
Being able to identify the passage type can help you apply the right approach: e.g. you might tackle Data Representation quickly since it's mainly scanning charts, whereas you might slow down and read more carefully for a Conflicting Viewpoints passage.
Raw score to scaled score: Your raw score (0-40) is the number of correct answers with no penalty for wrong answers, so always guess. This raw score converts to a scaled score from 1 to 36. The conversion varies slightly between tests, but typically you need about 30/40 correct to score in the mid-20s, while nearly perfect scores are required for a 36.
Current scoring system: Until 2025, your Composite score averages all four sections (English, Math, Reading, Science), making Science 25% of your overall score.
Enhanced ACT changes (2025): Starting in 2025, the Science section becomes optional and will not factor into your Composite score. Instead:
Always answer every question - random guessing is better than leaving blanks
Pacing: Focus on questions you can answer confidently, as each is worth the same
Current test-takers: Science counts equally with other sections for your Composite
2025 and beyond: Science becomes optional. Consider taking it if you're strong in science or applying to STEM programs. Check college policies as some may still expect Science scores
Supplemental scores: The ACT also reports STEM (Math+Science) and ELA (English+Reading+Writing) scores that provide additional context about your skills