It will really depend on the State and the School that you go to. I myself was able to be certified to teach after 4 years of school and that was just getting my Bachelors degree. Some schools do now put the Masters in with the Bachelors at one time so it could be 6 years of school and some let you get it while you are teaching. I would recommend to look into your State's or the State you want to teach in requirements. Then when you are looking at the school you want to attend they would have the classes needed and how long but you can also speak to an Advisor there and they can lay out a solid plan that will work for you!
Hope This Helps!