A. Length and width aren’t the only considerations when it comes to fitting a sofa into a room. There’s also volume. “Scale is the scariest issue faced by most people because they don’t understand it,” says interior designer Laura Barnett (700 N. Green St., 312-654-1706; laurabarnettdesigns.com). She says buyers need to take into account the girth of the sofa, the thickness of the cushions, and the height of the back, as well as length and width.

To make your new sofa look less whale-like, she says, get rid of any skinny wooden furniture in its vicinity. Try putting a big chair next to the sofa. If you can, make the walls and floor the same color as the sofa, or at least the walls.

And don’t forget throw pillows. “They should be gorgeous things—so gorgeous they’re all you can look at, and you don’t even see the sofa,” says Barnett. Her final thought is to put the sofa as far from the entrance as possible, and facing it. When you walk in, this distance will minimize the sofa’s size and you will see it only from the front, so you won’t notice how deep it is.

Interior designer Thomas Fitzgerald (2247 W. Belden Ave., 773-384-1111; thomasfitzgeraldinteriors.com) suggests hanging a big horizontal mirror over the sofa to distract attention from it and to enlarge the room. Use swing-arm wall lamps or floor lamps, so you don’t need side tables that might exaggerate the size of the sofa, he says. In front of the sofa, put a big glass-topped, iron-based coffee table that will add airiness and reduce fussiness. Finally, paint the walls a dark color to make them recede visually, which can also make the room look larger.

And if you haven’t bought your new sofa yet, be forewarned: “Furniture now is palace-sized, but furniture showrooms are big and have high ceilings, so looks are deceiving,” Barnett says.