What Is the Rule of Thirds?

The Rule of Thirds is a guiding principle in visual composition that has significantly influenced various fields, including interior design. It is adopted from photography and art to create balance, harmony, and visual interest within a space.

This rule is considered a powerful tool that can transform a room to feel beautifully arranged and aesthetically pleasing.

In its most common application, the Rule of Thirds involves imagining a space or an image divided into nine equal parts by two equally spaced horizontal lines and two equally spaced vertical lines.

The guideline suggests that important compositional elements or focal points should be placed along these imaginary lines or at their intersections. Aligning a subject with these points is believed to create more tension, energy, and interest in the composition compared to simply centering the subject.

In interior design, this principle can be applied to an entire room or even smaller decorative spaces like a bookshelf or a countertop.

In the context of interior design, the “Rule of Three” is often discussed in conjunction with or as a practical application of the Rule of Thirds, emphasizing the use of odd numbers for groupings. It suggests that items arranged in odd number groupings are more interesting, appealing, and natural than items arranged in even number groupings. Three is considered the minimum number to create a pattern or a repetitive composition.

Why Does the Rule of Thirds Work?

The Rule of Thirds and the concept of grouping in threes are deeply rooted in basic design principles and how the human brain processes visual information.

• Visual Interest and Engagement: Our brains are naturally drawn to odd numbers because they create a sense of balance and harmony while also challenging us mentally. When we see an odd number of objects, our eyes tend to move around the grouping more, making the visual experience more engaging and dynamic.
• Balance and Harmony: Odd numbers, particularly three, prevent a feeling of too much symmetry, which can appear forced, stiff, or monotonous. The slight asymmetry introduced by the Rule of Thirds maintains visual interest while still upholding order.
• Intuitive Appeal: Spaces that adhere to the Rule of Thirds feel intuitively balanced and engaging, as opposed to designs where elements are haphazardly placed or overly centered. This principle is believed to infuse a space with energy and create a well-balanced, inviting design. As one expert notes, “People think that when it comes to decor even numbers are best but its actually the odd group that wins the day”.

How to Apply the Rule of Thirds in Interior Design

The Rule of Thirds is a versatile tool that can be applied to various elements within an interior space:

• Furniture Arrangement:
  • Dividing the Room: Visualize dividing the room into thirds to guide furniture placement. For example, avoid placing a sofa directly in the center of a wall; instead, position it to align with one-third of the space.
  • Grouping: Think of main furniture groupings in odd numbers. A common arrangement is a sofa paired with two similarly scaled chairs, creating a balanced and inviting seating area. Alternatively, two sofas and a large coffee table, or a chair, side table, and lamp arrangement in a corner, can also follow this principle.
  • Defining Zones: In open-plan spaces, rugs or furniture groupings can be used to define zones based on the Rule of Thirds.
  • Focal Points: When styling a living room, furniture can be positioned two-thirds toward a focal point like a fireplace, leaving one-third open to maintain flow.
  • Bedrooms: A traditional bedroom layout with a bed and two nightstands lends itself well to the rule, with nightstands falling within the two bottom left and right thirds, and the bed, art, and lighting filling the rest of the grid.
• Accessories and Vignettes:
  • Grouping in Threes: Grouping decorative objects in threes is a tried-and-true technique that adds visual interest and balance. This can involve arranging similar items like three vases of varying shapes, heights, or sizes for a cohesive yet dynamic look.
  • Mixing Objects: Combine three different items, such as a candle, a small plant, and a decorative bowl, to create an intriguing vignette.
  • Stacks of Books: Arrange stacks of books in groups of three on a coffee table, bookshelf, or nightstand to add dimension and color.
  • Upholstered Pieces: For sofas, consider using three pillows instead of two, or five instead of four for larger sofas. A bed with four pillows can look more interesting with the addition of a throw pillow.
  • Varying Elements: When grouping items, vary their heights, shapes, and textures to add interest. The components don’t have to be matching; in fact, more variety is often better. Sometimes a pair or cluster of accessories can act as one part of the trio.
• Art Placement and Gallery Walls:
  • When hanging art, avoid centering it directly above furniture. Instead, align the artwork so its focal point matches one of the imaginary intersection points.
  • Gallery walls are an excellent way to implement the rule of three, from three large pieces in a row to a full wall of art. Play with these arrangements using an odd number of pieces, keeping cohesion by hanging similar art or using frames that are similar in material or color.
• Color Selection (The 60-30-10 Rule):
  • The Rule of Thirds also guides color choices through the “60-30-10 Rule”. This formula achieves perfect color balance in a room:
    • 60% Main Color: The dominant color, typically used on walls, large furniture pieces, or area rugs.
    • 30% Secondary Color: A supporting color, often used in upholstery, curtains, or accent walls.
    • 10% Accent Color: The boldest color, used sparingly to add interest and draw attention, such as in throw pillows, artwork, or decorative accessories.
  • This rule essentially breaks color groupings into three, creating cohesion with the 60/30 portions and interest with the 10 percent accent. It can be applied to any color scheme, including neutral palettes, by choosing three different colors and applying the equation.
• Lighting:
  • Lighting can be grouped in odd numbers for aesthetic appeal. A series of three pendant lights over a kitchen island looks balanced and pleasing.
  • A cluster of pendants in an odd number at varying heights can add visual interest in an entryway, dining room, or living space.
  • Lighting can also create a horizontal plane that defines the upper third of a space, serving as both a central point and a dividing line.
• Architectural Details and Other Applications:
  • The rule can be applied to texture, pattern, and architectural features.
  • Highlighting a grouping of three windows or using three beams across a ceiling can create visual interest and rhythm.
  • Different flooring or wall treatments can visually divide a larger room into thirds.
  • For rugs, applying the Rule of Thirds can ensure enough of the rug is showing to create a space with more breathing room and harmony.

Practical Tips for Applying the Rule of Thirds

• Start Small: Begin by applying the Rule of Thirds to smaller areas, such as a coffee table vignette or a bookcase. This allows you to get used to dividing designs into a grid and developing your eye before moving on to an entire floor plan.
• Use What You Have: Integrate existing architectural features like a fireplace or kitchen cabinetry as backgrounds for the Rule of Thirds, as they provide an easy starting point for mapping out your design.
• Be Flexible: The Rule of Thirds is a guideline, not an absolute rule. Adapt it to your specific space and style. Designers advise that using rules to the letter is often not very artistic.
• Focus on Focal Points: Create a central point that will fall at the middle dividing line, as this is where the eye will likely rest and where your focal point should be.
• Editing: When styling, editing is key. Once you think you have achieved an ideal composition, consider removing one small item, as you might not need it. White space can be beneficial.
• Balance Symmetry and Asymmetry: While odd numbers create interest, even numbers create symmetry. The Rule of Thirds helps balance both symmetry and asymmetry. If you have a pair of lamps on a console table (symmetry), add a group of three accessories by one of the lamps (asymmetry) to create a balanced yet not “stuffy” feel.

When to Break the Rule of Thirds

While powerful, the Rule of Thirds is not an absolute law. There are instances where even numbers can create the perfect balance or symmetry, particularly when a more formal look is desired.

For example, matching side chairs or table lamps on a console table often work best in pairs to create a formal and symmetrical appearance.

Understanding when and how to deviate from the Rule of Thirds can add sophistication and flexibility to your design approach.