What size snowboard do i need?

A good rule of thumb is the board should come up to about your chin. But before you go out and buy a board, I would suggest renting a board of the smaller size and see if it feels more comfortable than the larger size. It also depends on what you plan on doing with it. If you are going to a lot of park, I suggest a shorter, lighter board. If you plan on doing back country or groomers, a longer board probably would work better for you. The main thing is you have to feel comfortable on the board. If you feel awkward on the board than thats going to make your trip much worse.