How long would it take me to become fluent in french?

i plan on graduating high school having finished french V AP, i then plan on pursuing a major in french(double majoring in business/econ) i will do a semester abroad at some point and i also have money saved up so i could spend a summer over there so im thinking i will have at leas 6 or 7 months over there by the time i graduate. at what level could i be expected to be at upon graduation and if i were to spend some more time over there after graduation how long would it take me to achieve complete fluency/