I’m an international student. I converted my grades according to 4.0 GPA scale, but I’m not sure if the American universities count it this way. Based on my information below, would you say are my chances at getting into these universities (Harvard, Stanford or other)? Can you tell me whether I have still chances getting into good university with my sophomore GPA?
freshman: 3.88
sophomore: 2.77
junior: 3.9
overall: 3.52 (approx. 3.6 in 4.3 scale)
I attend one of the best and oldest high school in my country, but I’m not classified in the best 10 percent of my class.
You must remember that Stanford and Harvard have an holistic admissions process and so does most of the top selective universities. No one gets into any of the selective universities solely based on their high-school GPA. If you could tell us what your SAT scores, extracurricular achievements are, predicting your chances would be a lot easier. That way the prediction could better represent your ACTUAL chance of getting into Harvard or Stanford.
Also, bear in mind that a lot of students who apply to the prestigious institutions have a high-school GPA just like yours. Your GPA is quite high, but it is your extracurricular achievements and your personality that will set you apart and increase/decrease your chances of getting into college. Do you need financial aid?
Yes, I need financial aid but I read that Stanford expanded its financial support. Now it offers free tuition, room and board for families with annual income less than 65 000$ like Harvard. I don’t know whether it concers only American students.
I am not sure if Stanford is need-blind or not, but Harvard definitely is. Even though, these universities say that you they do not consider need while reviewing your application (and they certainly don’t), a student who needs less financial aid than you and has higher SAT scores or is a stronger applicant will be considered before you in the admissions process. The point I am trying to make is that you need to be an overall package to get into one of the top tier universities.
It’s also worth keeping in mind that these universities are sometimes NOT need-blind for international students, only American students. So you should check on what their policies are regarding financial aid for internationals.
What about the 10% of the students at your school that rank above you? Have you considered that they might want to go to a school like Harvard or Stanford (for free), too?
The admit rate for international applicants at Harvard and Stanford is around 3%. Many of those people will have outstanding awards and achievements. The admit rate at Stanford with applicants whose GPA was under 3.7 was 1%, including athletic recruits; the admit rate at Stanford was also under 1% for those who ranked outside the top 10% of their class. Unfortunately, a 3.52 GPA and outside the top 10% for an international applicant is going to have an extremely remote chance, unless you have done truly extraordinary things outside of your academics, and even then it will probably be a long shot.
Without knowing more it is hard to be encouraging. The odds are stacked against you.
Keep in mind that there are MANY amazing schools in the US that would love to have you. Just because the top of the top may be out of reach, it doesn’t mean that you’re bound to stay in your country for college. Take a look at the US News rankings of good schools in the US (broken down by major, public/private, location, etc.) and see if you can find a match.
My grades in junior year are expected. Fortunatelly, I have still one year to prepare myself to study in the U.S. and gain more achievements. Yale, Princeton, Dartmouth and Amherst are very good as well. 
If you have one more year, I suggest that you start preparing for the SAT right away if you have not already done so. You also have to work hard to achieve the expected GPA that you have mentioned in your post. And don’t forget to stay involved in extracurricular activities. If you do this, next year you’ll be in a good position to apply to some to the prestigious universities. There are a lot of very good schools besides the ivies, so do some college search and choose a college that you think will be welcoming for a person like you. Believe me, you will feel better at a college where you can make yourself at home.
I think you are being unrealistic. But come back in a year when your junior grades are real.