Straight answers
When should I take the SAT?
Most students take the SAT for the first time in fall or spring of junior year (11th grade) — early enough to leave room for a retake in senior fall before college application deadlines, but late enough to have covered most of the tested math content in school.
There's no single mandatory date, but the timing most counselors recommend balances two things: enough coursework completed (especially Algebra II-level math) to be ready for the content, and enough runway left to retake the test if a student wants a second attempt before applications are due.
A common path: PSAT in 10th grade (low-stakes, informative), SAT in spring of junior year, then an optional retake in fall of senior year if there's time and reason to. Early-decision or early-action applicants especially benefit from testing by junior spring, since fall senior-year deadlines can be as early as October or November.
There's flexibility here — some students test earlier if they're ready, some wait if they need more prep time, and increasingly some skip standardized testing altogether at test-optional schools (see our answer on whether the SAT is still required). The right timing depends on the student and the schools on their list, not a universal rule.
Whatever the timeline, checking each target school's testing policy and deadlines directly is worth doing early — it changes how much runway actually exists.