In the prime of your adulthood, you might not be Googling the best sleeper sofas with the fervor you did in college (when brick-like, nearly-scraping-the-floor futons were pretty much the norm).

Sleeper sofas come in a range of sizes, from loveseats or chairs-and-a-half that convert into twin-sized beds and full-sized sofas that contain queen- or king-sized mattresses. Like buying a sofa ...