Of all the differences between these two tests, Math is the most significant (other than the fact that the ACT has a Science section and the SAT test does not have Science.) Most students naturally do better on one of these than the other.  The best way to find out which is best is to take a “mock” ACT test and a” mock” SAT test and compare the scores. Another way is to take Vogel Prep’s highly predictive “ACT vs SAT Comparison Test”. There are no charges for these tests and follow-up consultations at Vogel Prep.