You'll be able to leave the theater as soon as the credits start rolling.
One of the more annoying/fun little things that is cropping up in more and more movies these days is the post-credits "stinger" - a short scene that plays after the credits, either hinting at a sequel or just showing a silly little bit of footage that may not have fit in anywhere else in the film. Most prevalent in super hero movies, there is now a website dedicated to letting you know if you have to stick around after the credits. Thankfully/regretfully, director J.J. Abrams has revealed that Star Wars: Episode VII will not have a post-credits scene.
While it was pretty unlikely we would be getting a teaser for Epsiode VIII so early on, some fans were hoping to get a sneak peak at 2016's Rogue One at the end of the film.
Abrams, speaking to several journalists at a press conference (as reported by Screen Crush) went on to stress that every scene he wanted to put in the movie was in it, eliminating the need for a "secret" post-credits scene. "All of the scenes are actually in the movie," he said.
Personally, I'm overjoyed at this. I hate sitting around in a theater awkwardly when the credits start rolling, asking around "does anyone know if there's a stinger?" or looking it up on my phone.
Source: Screen Crush