Designers Always Follow This One Rule In Every Design Project

If you've ever wished for a magic formula to help you decorate a room, then the rule of thirds in interior design could be exactly what you've been looking for. This trick can help you visualize exactly how living room furniture should be arranged or a built-in bookcase should be styled, all by using a three-by-three grid.

Want to learn exactly what this interior design formula entails and how you can use it in your home? Here's what you need to know about the rule of thirds, according to interior designers.

What Is the Rule of Thirds?

With the rule of thirds, you'll divide any space into a grid that includes nine boxes formed by a three-by-three grid. You then use that grid to help place items and make sure there's visual balance throughout the space.

"The rule of thirds third is deeply rooted in basic design principles," says Cathy Hobbs, an interior designer who recently wrote a book on the recipes and hacks that go into perfecting a room's design. "It relates to creating a sense of proper balance and proportion, whether it’s a kitchen island or windows or even bookshelves."

This can be used in a room or even a smaller decorative space. You'll look at each "box," from left to right and top to bottom, to ensure that the weight of the items makes sense. You can use this to break apart the space and see how the colors, textures, and lines flow throughout the room.

To help anchor the grid, Hobbs recommends creating a center point that will fall at the middle dividing line.

"When you are dividing a space like a countertop into thirds, keep in mind that that central middle section is where the eye will likely rest that is where you should have your focal point as it relates to your decor," she says.

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6 Tips to Use the Rule of Thirds in Your Home

"The rule of thirds creates balance and visual interest within a space," says interior designer Elizabeth Vergara. "I use it regularly when arranging furniture or artwork, dividing the room into sections that feel naturally harmonious."

Here's how to use the rule of thirds in your home:

Start Small

It can be difficult to jump into using the rule of thirds with something like a dining room furniture arrangement, where you have large items to work with. Instead, start small. Use a coffee table vignette or a bookcase to get used to splitting your designs into a grid and working with the rule of thirds. As you get more confident and develop your eye, then move on to an entire floor plan.

Find a Focal Point

Use one large item as the starting point for the rule of thirds.

"When styling a living room, I might position two-thirds of the furniture toward a focal point like a fireplace, leaving one-third open to maintain flow," Vergara say. "This principle also guides how I place decor—ensuring each area feels intentional without overcrowding or imbalance."

Use What You Have

If you have a fireplace or kitchen cabinetry in the space, use those to serve as the background of the rule of thirds. They aren't going anywhere, so they can help you map out the plan and give you an easy starting point.

Apply the Rule of Thirds to Rugs

The rule of thirds can also apply to rugs. People often go too small but, if you use the rule of thirds, you'll guarantee you have enough of the rug showing to create a space that has more breathing room and harmony.

Leverage Lighting

Lighting can create a horizontal plane that helps define the upper third of your space. Use it as both a central point and a dividing line, and don't discount its visual weight within a room.

Use the Rule of Thirds in the Bedroom

A traditional bedroom furniture layout, with a bed and two nightstands, lends itself perfectly to the rule of thirds. Your nightstands should fall within the two bottom left and right thirds, and you'll fill the rest of the grid with art, lighting, and, of course, your bed.