When to start SAT prep?

I am a sophomore. When should I start SAT prep?

Next summer. You can prep for SAT and PSAT at the same time.

I’d suggest taking a practice test under actual conditions (timing, on paper, etc.) now to understand what it’s all about. Use the results/diagnostic (Khan is helpful) to identify areas to focus on. Start a program of light review - maybe a few hours a month - to start building up the fundamentals for later.

Real prep - practice exams weekly/bi-weekly and a few hours a week of study - should start 2-4 months before the actual test. I agree that taking your first real SAT in the fall of Junior year is a good plan.

One thing to remember is that you may not have studied some of the material on the SAT. Prep cannot replace the year long courses in which they teach the math on which you are tested during the SATs. The same can be said for the English sections.

Any SAT you take now will likely have a low score because you lack this material, and therefore would not be a good predictor of how well you will do on the PSAT or SAT. The main benefit from prepping is increased familiarity with the SAT format and testing methodology.