I have about three months to study for the ACT, and I'm trying to raise my score from a 27 to a 31. How many hours per week should I study? How many hours should I try to fit in total?
For a 4 point improvement, I would recommend studying for anywhere from 40 to 60 hours total. If you're a very focused studier, you may be fine with a shorter amount of time. If you tend to get distracted or don't learn from your mistakes as quickly, you should think about studying for longer.
Three months is around 15 weeks of studying. On average, four hours a week should be enough time for you to see the improvements you want by the time the test rolls around. Before you start studying, take a full official practice test to see which sections and types of questions tend to give you the most problems.