Five Differences Between ACT and SAT

1. Length

The SAT is 3 hours, 45 minutes long, plus breaks, etc.
The ACT is 2 hours, 55 minutes long, plus breaks, etc. This does not include the writing portion, which adds another 30 minutes if you choose to take it.

2. Format

The SAT has ten sections: 3 critical reading, 3 math, 3 writing, and one unscored section they use to try out new test questions. The test always begins with the essay and ends with a 10-minute writing section. The second section through the seventh are 25 minutes long; sections eight and nine are 20 minutes. They can come in any order -- reading, math, reading, writing, etc.

The ACT has four sections that always appear in the same order:

English: 45 minutes

Math: 60 minutes

Reading: 35 minutes

Science: 35 minutes

3. The ACT English tests punctuation, grammar, and syntax. The SAT focuses on vocabulary as well as grammar.

4. The ACT has a science section. The SAT does not.

5. The SAT claims to test reasoning and problem-solving ability. The ACT claims to test curriculum-based knowledge.

Here is what the College Board says about the SAT:
"It tests students' knowledge of subjects that are necessary for college success: reading, writing, and mathematics. The SAT assesses the critical thinking skills students need for academic success in college—skills that students learned in high school."

Here is what the ACT makers say about the ACT:
"The ACT is curriculum-based. The ACT is not an aptitude or an IQ test. Instead, the questions on the ACT are directly related to what students have learned in high school courses in English, mathematics, and science. Because the ACT tests are based on what is taught in the high school curriculum, students are generally more comfortable with the ACT than they are with traditional aptitude tests or tests with narrower content."