How do US universities evaluate Spanish transcripts, which have?
The best US research universities will deal with your record on its own terms; they will know how to evaluate a Spanish transcript.. If they need an outside evaluation (for example, from WES), they will ask for it. For a PhD, your academic record in your intended field should be very strong. Your letters of recommendation and especially, your research and career plans, count for a great deal. Unlike in the case of undergraduate admissions, the department in question will play a large role in the decision. Write to the department now, so that you can plan. Look for the name of the person who is serving as Director of Graduate Studies. And good luck to you!