Depends entirely on your major and how much AP credit you have.
You need to have a minimum of 180 units to graduate. Here are the units required for each major:
http://exploredegrees.stanford.edu/undergraduatemajorunitreq/#text
As you can see, Political Science only requires 70 units, whereas Computer Science requires between 96 and 106 units. But these figures don’t consider AP credit:
https://studentaffairs.stanford.edu/registrar/students/ap-charts
If you’ve 5’d AP Calculus BC, AP Physics C, AP Chemistry, and a language AP test that Stanford accepts, then you’ve already lopped 35 units off of the requirements for the CS degree (slightly more than two quarters’ worth of coursework). Stanford will accept up to 45 units of AP/transfer credit, which is equivalent to about a year’s worth of coursework.
The difference between the units that are required for your major and the 180 units required to graduate are units that you can do lots of things with. You do need to fulfill your GenEd requirements, which we call the WAYS (https://undergrad.stanford.edu/programs/ways/ways), but you can also take random classes that interest you (many of these end up counting as WAYS), study abroad, work on a second major or a minor, and/or work on a graduate degree. As far as the last option is concerned, many Stanford students opt to stay on for a fifth year to get a master’s degree. The practice is called co-terming, and in order to finish the master’s in the fifth year, students typically need to have done some of the graduate coursework while still an undergraduate.
Here’s Stanford’s course catalog for this year:
http://explorecourses.stanford.edu/
And here are all requirements for all degrees: