How many letters of recommendation is good for a college app?

You should contact the admissions office of the institution if that information is not on their website, but for most schools you don't need more than two, three at the most. Some, like the University of Washington, do not want any letters of recommendation.

It's a bit early to be collecting recommendation letters, though good for you that you have so many people willing to write for you when time comes.

From what I remember, the common app requires 2 teacher recommendations, plus 1 from the school counselor. However, each school sets its own requirements and expectations for how many letters they'd like.

So -- I wouldn't collect any more for now. Just keep in touch with the teachers who might write the best letters for you. Also keep your mind open to having letter writers next year; sometimes, it can be helpful to have teachers of more advanced courses speak to your academic promise.

3 is enough...5 is too many