Norwegian scientists develop the technology to shrink humans to five inches in an effort to combat global overpopulation. The permanent procedure also provides the bonus of a more economical lifestyle, since smaller things cost less.

Hoping for a better life, Paul (Matt Damon) and his wife Audrey (Kristen Wiig) decide to abandon their old lives. Unfortunately for Paul, downsizing comes with a new list of complications, including Audrey backing out at the last minute.