Adding a rug in your bedroom is a cost-effective way to create cohesion and coziness in your sleep sanctuary. But if you choose the wrong rugs, it can mess with your desired design aesthetic and the tranquility of the space. A rug does more than just complement your decor, so it isn’t just about picking pattern and material.

Heather Mastrangeli, an interior designer and owner of Innovatus Design, says choosing the right rug size and placement creates a sense of balance and proportion within the space.

“A small rug will get lost within the bedroom, especially if the bed is placed on top of it,” she says. “While a rug that is too large will create an overcrowded look and make the bed look small and unwelcoming.”

Check out these expert-approved tips if you’re struggling to choose the right rug for your bed and the surrounding space. (And don’t forget to explore these useful tricks to get rug under bed.)

Rug Under Bed Rules

Interior design rules aren’t set in stone, and there’s no one-size-fits-all formula for choosing the right type of rug. However, as Artem Kropovinsky, founder and principal designer at Arsight, says, “An undersized rug can make the room feel fractured, while an oversized one risks overwhelming its nuances.”

Have you noted the room dimensions and furniture measurements, but still aren’t sure where to start when shopping for your new rug? Understanding some of the accepted do’s and don’ts for size and placement of under-bed rugs helps you avoid a design disaster.

• “A rug beneath the bed should generously extend at least 18 to 24 inches on either side,” Kropovinsky says. Keeping all four legs of the bed on the rug ensures a spacious, connected and balanced feel. And no matter what side of the bed you roll out of, your feet will meet a warm, sound-absorbing surface rather than a cold floor.

• Mastrangeli recommends allowing at least a foot’s breathing space between the rug edges and the bedroom walls to create an airy aesthetic.

• She also suggests leaving at least three feet of rug on either side of the bed to provide ample space for your bedroom nightstands. “If your nightstands are wider than three feet, enlarge the rug accordingly,” she says.

• And don’t forget to consider symmetry. Ensuring there’s an equal amount of rug extending beyond each side of the bed brings a sense of balance and order — important in a minimalist bedroom designed for relaxation.

• Above all, Mastrangeli says you should ensure there’s visible floor space. This differentiates between the rug and flooring beneath when you’re trying to make a design statement.

What Size Rug for a King Bed?

Krapovinsky says king beds demand grandeur. Start your search with a rug that’s around 10- by 14-ft., he says, while nodding to the layout of the room. In a smallish bedroom, Mastrangeli says a 9- by 12-ft. rug can do the trick, though an 8- by 10-ft. model might work in a tiny one.

If the space is opulent and exceptionally roomy, and if you can stretch your budget, go even larger for a truly luxurious bedroom vibe. But always remember to allow at least a foot of space between the rug and the walls around the room.

If your budget won’t stretch to fit a grand rug under your king bed, consider using runners on either side or at the foot of the bed instead. Ensuring they extend beyond the ends of the bed creates a roomy, rather than restricted, feeling of space.

And when you’re going big, Mastrangeli says, look out for vents in the floor. “Vents are often under windows, and sometimes they land right where a rug should be,” she says. “Rugs can be cut and bound professionally to accommodate holes for vents, or the space can be designed around them.”

What Size Rug for a Queen Bed?

The biggest mistake people make when selecting the best area rug for their bedroom is going too small. Krapovinsky recommends a 9- by 12-ft. rug under a queen bed, with Mastrangeli adding an 8- by 10-ft. model also works well. If you don’t have nightstands at the sides of the bed, a 7- by 9-ft. rug will do.

If your budget or favorite rug design doesn’t let you go big enough and your bed is pushed up against a wall, you could always choose a slightly shorter rug. Position it so the lower two-thirds of the bed sits on it without the rug interfering with any nightstands. That way, you’re adding a cozy, textural element where your feet land in the morning.

This also works if you have a bedroom storage bench or sofa at the end of the bed, and want to ensure a standard-size rug will extend beyond this for a balanced vibe.

What Size Rug for Full or Twin Beds?

Krapovinsky suggests an 8- by 10-ft. rug for a pair of twin beds. Mastrangeli says a 6- by 9-ft. rug for a full bed and a 5- by 8-ft. one for a twin bed are also good starting points.

Mastrangeli says sometimes large rugs just don’t seem right for twin beds. “In that case, a carpet runner on each side of the bed is also a good option,” she says. “The runner should be at least 30 inches wide and roughly five feet long.”

If you don’t want a rug to sit under two twin beds or at the side of both, one rug in between the beds also works.