The highest possible score anyone can achieve on the ACT is a composite score of 36.
As you probably know, the ACT comprises four sub-tests:
On each one of those sections, the number of questions you get right equals your raw score. ACT then converts that raw score into a scaled score ranging from 1 to 36.
You also get a composite score, which is the average of your four scaled scores. Your composite score corresponds to a percentile rank that relates your test performance to that of the whole cohort of students who took the ACT when you did. If you’re in the 75th percentile in Science (for example), that means you did better than 75 percent of students on that part of the test.
That stellar 36 is the composite that you’d get if you achieved a near-flawless 36 on all four sub-tests.
(How rare is that? ACT reports that out of the 1,914,817 students in the class of 2018 who took the ACT, 3,741 earned a composite 36. That’s just 0.195 percent).
The highest possible score on the essay is 12. It’s scored separately and doesn’t affect any of your other scores.
This is where the “standardized” part of “standardized test” comes in.
No matter how careful the test writers are, some ACTs are going to be slightly harder or easier than others.
To even it out, ACT adjusts the significance of raw scores from one test to the next.
For example, a scaled score of 27 in Reading may correspond to the 82nd percentile in June and the 84th percentile in September.
So when you ask, What’s the highest ACT score? remember that you need to be thinking in terms of scaled scores.
So what’s the highest possible ACT score? A composite 36.
What’s a good score? A score that will help you get accepted at the school of your choice? That’s a more complicated question. The answer depends on a few factors:
For some extra help interpreting your scores, take a look at the ACT site. To know where to start looking for a good test prep to help assure a high test score, check out The Princeton Review, ACT Online, Kaplan and others.