The ACT and the SAT are fundamentally similar: they’re standardized tests that you take as part of the college admissions process to demonstrate your competence to the schools you may want to attend. But despite their identical purposes, the tests themselves have some important differences.
The ACT may be a better choice for you if you struggle with math. All of the math questions on the ACT are multiple choice, meaning you have a chance of guessing correctly even if you can’t come up with the precise answer. You’re also allowed to use a calculator on all of the math questions.
The SAT, on the other hand, has some fill-in-the-blank style math questions -- which could be a nightmare if your strengths lie in other areas. It also only allows the use of a calculator in one of the two math sections. Both of these factors make this section potentially more challenging on the SAT.
One of the biggest differences between the ACT and the SAT is that the ACT includes a science section. While you have the option of taking an SAT Subject Test in science, the basic SAT does not include a science portion. To be fair, the ACT’s science section is intended to measure your critical thinking skills rather than your science knowledge, but it may still be intimidating if science is your weak point.
The presence of a science section is less of a deciding factor if you’re good at science than if you’re bad at it. If you’re confident in your science skills, you can demonstrate that to colleges by taking an SAT Subject Test; the ACT isn’t your only chance to show off your science expertise.
If you’re bad at science-related topics, however, the SAT becomes a more compelling option. You can avoid revealing this weakness by taking the SAT and choosing subject tests that play to your strengths.
The SAT allows you to demonstrate knowledge and capability in subjects not covered through the main portion of the test by taking the SAT Subject Tests. Options here include various foreign languages, world or US history, literature, chemistry, physics, and so on. If you have a strength in one of these areas, this is a great way of showing it to schools.
The ACT does not offer subject tests. This may be good or bad; it means fewer tests to worry about, but may not let you adequately show all your skills.
This isn’t necessarily an either-or choice. Some schools require subject tests even if you opt for the ACT as your primary test. Others waive the subject test requirements if you opted to take the ACT instead of the SAT. Still others will waive the subject test requirements only if you take the optional writing portion of the ACT.
Speed and Timing
The SAT and the ACT are very nearly the same length, at 3:00 and 2:55 respectively. The larger difference is the number of questions; the ACT has quite a few more than the SAT. If you have a hard time focusing for extended periods or do better when you have longer to mull a question over, the ACT may pose a problem in this regard.
The Final Decision
At this point, if you’re still not sure whether to focus on the SAT or the ACT, the best solution is to take a couple of practice tests for each. This will allow you to have some idea of how you might score on the actual test, and reveal which is better suited to your particular strengths.
Another option that may work for you -- though it will take more time and money -- is to simply take both tests. This way you cover all your bases, and can submit the one that has a better result to colleges. Even though this may require both SAT prep and ACT prep, the option to use either score is undoubtedly a benefit.