Home › Guides › Is ACT Science Optional?
Is ACT Science Optional? Yes. Here's What That Means
Updated June 2026 · Verified against the enhanced ACT format
Yes, the ACT Science section is optional on the enhanced ACT, which rolled out nationally in 2025 and into spring 2026 for school-day testing. If you opt in, Science is 40 questions in 40 minutes (about 60 seconds per question), it gets its own separate score, and it does not count toward your 1-36 Composite at all.
Short answer: Science is opt-in. Your Composite is the average of English, Math, and Reading only. A perfect Science section can't raise your Composite, and a rough one can't lower it. The only reasons to take it are that a target college wants it or you're a STEM applicant who benefits from showing the score.
Yes, ACT Science is optional (and scored separately)
For decades, Science was a mandatory fourth section baked into the Composite. The enhanced ACT changed that. Science now sits alongside the optional Writing essay: you register for it if you want it, skip it if you don't, and either way your Composite is calculated from the three core sections.
If you do take Science, colleges can see that separate score on your report. If you skip it, there's simply no Science score. There is no penalty, asterisk, or "incomplete" flag for skipping an optional section.
What changed: the enhanced ACT format
Here's the full enhanced-ACT lineup so you can see where Science fits:
| Section | Questions | Time | Status |
|---|---|---|---|
| English | 50 | 35 min | Core. Counts toward Composite |
| Math | 45 | 50 min | Core. Counts toward Composite |
| Reading | 36 | 40 min | Core. Counts toward Composite |
| Science | 40 | 40 min | Optional. Scored separately |
| Writing (essay) | 1 prompt | 40 min | Optional. Scored separately |
The core test runs about 125 minutes. Opting into Science adds 40 minutes on top of that. Two more changes worth knowing: Math now has four answer choices instead of five (with no formula sheet provided), and the digital version is linear, not adaptive, with a basic on-screen calculator. For the full picture of how this stacks up against the SAT, see ACT vs SAT in 2026.
How your Composite is calculated now
This is the fact most people searching this question actually want: the 1-36 Composite is the average of your English, Math, and Reading scores. Period. Science is not in the formula.
Say you score English 24, Math 22, Reading 26. That averages to a 24 Composite. Add a Science score of 30 to that report, or a Science score of 15, and the Composite is still 24. Science can decorate your score report; it cannot move the headline number.
For context on what that headline number means (the national average Composite sits roughly in the 19-20 range), read what's a good ACT score.
Should you take the Science section? A decision checklist
Don't guess. Work through this in order:
- Check every target college's published testing requirements. Go to each school's own admissions website and read the current-cycle testing policy. Policies vary by school and change year to year, so do not rely on forums, friends, or what was true when your older sibling applied. If even one school on your list wants the Science score, that settles it: take it.
- STEM-leaning? You have the strongest case for opting in. If you're applying to engineering, pre-med tracks, computer science, or anything data-heavy, a strong Science score is relevant evidence that costs you 40 minutes. It can only add information, since it can't touch your Composite.
- Check any state or scholarship rules that apply to you. If you're testing through a school-day program or applying for a scholarship with its own testing requirements, those rules are published too. Verify them the same way: from the source.
- Nobody on your list asks for it? Then Science is extra time with zero Composite impact. Skipping it is a legitimate, rational choice, and you can spend the prep hours on the three sections that actually move your number. Start with pacing strategy, since timing is where most core-section points leak.
What's actually on ACT Science: 40 questions, 40 minutes
Here's the part nobody tells you: ACT Science is barely a science test. It's a graph-and-data reading test wearing a lab coat. You don't need to recall the Krebs cycle or balance chemical equations. Most answers sit directly in the figures, tables, and short passages on the page.
Three things carry you through most of the section:
- Read the figures first. Axes, units, and trends answer the majority of questions. The paragraphs are mostly setup.
- Know the variable vocabulary. Independent variable = the thing the researchers changed on purpose. Dependent variable = the thing they measured. Control = the baseline condition used for comparison.
- Conflicting Viewpoints passages hinge on the disagreement. Two scientists will agree on almost everything except one point. Find that one point before touching the questions.
Try it: original ACT-style mini questions
A student adds 5 g of salt to 200 mL of water at three different temperatures and records how long the salt takes to dissolve fully:
| Trial | Water temperature | Dissolving time |
|---|---|---|
| 1 | 10°C | 110 s |
| 2 | 25°C | 70 s |
| 3 | 40°C | 35 s |
Q1. As water temperature increases, dissolving time: A) increases B) decreases C) stays the same D) cannot be determined
Answer: B. Read straight down the columns: temperature climbs from 10°C to 40°C while time falls from 110 s to 35 s. Trend questions like this are pure table reading. No chemistry knowledge required.
Q2. In this experiment, the independent variable is: A) dissolving time B) water temperature C) the mass of salt D) the volume of water
Answer: B. The researcher deliberately changed the temperature between trials, so temperature is independent. Dissolving time was measured (dependent), and salt mass and water volume were held constant (controls).
Q3. In a separate study, plants grew 4 cm/week at 20°C and 8 cm/week at 30°C. The growth rate at 25°C was most likely closest to: A) 2 cm/week B) 4 cm/week C) 6 cm/week D) 10 cm/week
Answer: C. 25°C sits halfway between the two measured temperatures, so estimate halfway between the two measured rates: about 6 cm/week. This is interpolation, one of the most common ACT Science moves.
Q4. Scientist 1 argues lake algae blooms are driven mainly by fertilizer runoff. Scientist 2 argues warming water temperatures are the main driver. Both note that blooms peak in summer. The scientists disagree about: A) whether blooms peak in summer B) whether algae live in the lake C) the primary cause of the blooms D) whether the lake contains fertilizer
Answer: C. Both accept that blooms happen and peak in summer; they split only on the main cause. Conflicting Viewpoints questions almost always live on that single point of disagreement, so isolate it first.
How to prep if you opt in
If a school on your list wants Science, or you're a STEM applicant taking it for signal, prep is straightforward:
- Never leave a blank. There is no penalty for wrong answers anywhere on the ACT. Guess on everything you can't reach.
- Train at 60 seconds per question. 40 questions in 40 minutes is the budget. Practice with a timer from day one; our pacing guide covers section-by-section targets.
- Check axes and units before answer choices. Wrong-unit traps (seconds vs minutes, mL vs L) are the section's favorite trick.
- Figures first, text second. For data passages, skim the setup and go straight to the tables and graphs. Return to the text only when a question forces you to.
- For Conflicting Viewpoints, write down the disagreement. One sentence: "S1 says X causes it, S2 says Y." Every question gets easier after that.
Want real reps? The free practice app has an ACT-style Science passage with instant explanations for every answer, plus a built-in pace timer set to 60 seconds per question. No signup, no paywall.
Start free Science practiceFAQ
Is the ACT Science section optional?
Yes. On the enhanced ACT (rolled out 2025 into spring 2026), Science is optional: 40 questions in 40 minutes, scored separately. It does not count toward your 1-36 Composite.
Does ACT Science affect your Composite score?
No. The Composite is the average of English, Math, and Reading only. Science gets its own separate score that colleges can see if you take it.
Should I take the ACT Science section?
Check your target colleges' published testing requirements. If a school asks for it, or you're applying to STEM programs, take it. Otherwise it adds 40 minutes with no effect on your Composite.