Most of us studied 3 to 4 months full-time, or 5 to 6 months if studying part-time around school or work. That works out to roughly 300 to 500 total hours, though the honest answer depends far more on your existing content base than on the calendar.
The real signal to follow is your full-length practice test scores, not a fixed study calendar. Take a diagnostic first, work through content review, then shift the majority of your remaining time to practice questions and full-lengths. Don't sit for the real exam just to "see how it goes" — every attempt shows up permanently on your record, which is a big part of why a structured, tiered study plan tends to outperform an open-ended one.