<p>32 are required for graduation. That's four classes each semester for eight semesters. You can have up to two AP classes counted for credits. Many people end up with more than 32 credits, through taking phys ed, music, dance, art, science lab classes on top of their regular course load.</p>
<p>In the sciences, you can stay for a fifth year, tuition-free, and get a MA.</p>