It depends where you go to school now a day but my father-in-law has been a Psychologist for approx. 36yrs and attended school for 7yrs and is always doing training of sorts as well.
I might add, it also depends on which program of study you are pursing. In others words, a Masters in School Psychology would take longer to complete than a Masters in Behavioral Science because of the number of credits required. In general, Masters degrees can run anywhere from 30 credits to over 60 credits. How long it takes to complete the the degree will also depend on whether a student is taking the program of study on a full-time or part-time bases. Thus, it's difficult to say how long it will take, without knowing the specifics. A Masters then can take anywhere from one year to several years depending.