ACT® · Science: The Section, the Clock, and the Optional Decision
Whether to Take the Optional Science Section
The optional Science section costs 40 extra minutes and produces a separate Science score plus a STEM score, but it never changes the Composite, which is built only from English, math and reading.
The Composite score is fixed as the average of three section scores: English, math and reading. Science sits beside those three, not inside them. Sitting for the extra 40 minutes cannot raise or lower the Composite by even a tenth of a point, because that number never looks at Science in the first place. So the decision to take it has nothing to do with protecting or boosting the Composite.
What the Science section actually buys is a separate Science score, and that Science score combines with the math score to generate a STEM score. Neither of those two numbers exists without sitting for Science. A student who skips it simply has no Science score and no STEM score to report, full stop.
That makes the real question not 'will this hurt my Composite' but 'does any program I'm applying to care about a STEM score.' Engineering, computer science and other technical programs sometimes look at it as a side signal of readiness. A student aiming at those programs gains a data point competitors who skipped Science cannot offer. A student applying to programs that never glance at STEM scores gains little beyond 40 minutes of fatigue, since the Science score and STEM score will simply go unused. The decision connects directly to the timing and stamina tradeoff of the whole test: Science comes last, after English, math and reading have already drained the clock, so the choice to sit for it is really a bet that the extra data is worth the extra tiredness.
Key terms
- Composite score
- The average of the English, math and reading section scores only.
- Science score
- A separate section score produced only if a student sits the optional 40 minute Science section.
- STEM score
- A combined score built from the math and Science section scores, unavailable without taking Science.
- Optional section
- A test section a student can choose to skip without affecting the required scores colleges receive.
Watch it explained
- How it worksHow does taking ACT Science unlock a STEM score that English, math and reading alone can never produce?
- How it worksWalk me through which students gain most from the optional Science section and which gain almost nothing.
- Common mistakeWhy isn't skipping the Science section a free way to raise the Composite you report to colleges?
Check yourself
End of topic.