Good ACT Score Low SAT Score for Stanford and UPENN?

I'm planning on applying to Stanford and UPENN, which both require students to submit all standardized test scores. My problem is that I have a 33 ACT score but only a 2100 SAT score. The 33 ACT score is at or above average for these schools, but the 2100 is solidly below average. I also have a particularly low Critical Reading score (630). Should I be worried about my chances based on my SAT score?

Your SAT score is not low enough to make a strong negative impact on your chances at these schools. When Stanford and UPENN see that you have a more impressive ACT score, they won't be too concerned with your SAT score. I would only tell you to worry if your SAT score was abnormally low in comparison to your ACT score. The two scores still show some degree of consistency. They'll just assume that you're someone who happened to be better suited to the format of the ACT. These schools are so competitive that there's always a chance of rejection, but your SAT score won't make or break your application in this scenario.