Interior Design 101: The Rule of Three

There is an important “rule” in design that can be a powerful tool when decorating your home.  It has the power to take a room that just doesn’t feel right, and transform it into a room that works.  And, the best part is that it doesn’t take a lot of money or effort to apply this rule.  What is it, you ask?  It is “The Rule of Three.”  

The rule, or guideline if you prefer, simply states that things arranged in odd numbers are more visually appealing to the human eye.  Our brains just love odd numbers because they challenge us mentally.  Groupings of items in odd numbers tend to look dynamic and more natural to us. Whereas, things that are grouped in even numbers tend to look stale, “staged,” and cold.  Three seems to be the magic number for interior design, but the rule also applies nicely for groupings of five or seven.  And, not only does the “odd” number rule apply to interior design, but the principle shows up in many other areas of life from architecture to photography, and even religion.

So, how can you apply the Rule of Three in your home? Here’s some ideas:


You know how some people just seem to have a knack for arranging things in a way that looks effortless and beautiful? Well, chances are that their little secret is the Rule of Three.  Grouping accessories in threes is a tried and true decorating technique.  Here are some things you can do:

  • Group three similar objects (like glass bottles).  The objects can be similar in color, but different shapes or sizes.
  • Group three different objects together to create an interesting vignette
  • Group stacks of books in threes

Here is an example of some beautiful bookshelves from Joanna Gaines of Magnolia Homes. See the three similar glass bottles on the top, and the three different bottles on the bottom shelf? And on the middle shelf, there is a unique arrangement of a book, antique scale, and bird’s nest (a grouping of three).

decorating bookshelves

Source: Magnolia Homes

Furniture Arranging

If you look through design magazines or home catalogs, you may notice that often times the living room furniture is arranged in sets of three.  A sofa and two chairs, for example.  The Rule of Three strikes again! When it comes to furniture, your best option is to choose pieces that are similar in size and shape, although the colors can be different.  Here’s a nice example from Ethan Allen.  Notice the three pillows on the loveseat and the stack of three books on the coffee table?

arranging furniture rule of three

Source: Ethan Allen


Would you believe that the Rule of Three also applies to choosing colors for a room?  No joke!  There is even an “equation” for choosing the colors.  The equation says that when choosing colors for a room, you should select:

  • a main color for the space that makes up 60%
  • a secondary color that makes up 30%
  • and an accent color that makes up 10%

The colors don’t need to be bold or opposites on the color wheel to work…you can choose colors that are soothing and neutral, too.  Just pick three different colors, and apply the equation to create a pleasing look for your space. Here’s a great example of applying the 60-30-10 rule from Maria Killam.

choosing paint colors 60/30/10 rule

Source: Maria Killam

Other Ways to Apply the Rule of Three

  • Lighting – three pendent lights hanging over a kitchen island
  • Fabrics – combining different patterns that have similar colors (like paisley, flowers, and stripes)
  • Architectural Details – highlight a grouping of three windows
  • Artwork – Create a grouping of three similar framed pieces of art, or three decorative items (like plates) on the wall

The great thing about the Rule of Three is that you generally don’t need to go out shopping for new items, you simply need to take a look at your current space, and see how you can apply the rule to make some minor (but significant) improvements. Just have fun with it!

Have any of you tried to apply the Rule of Three in your home decorating?

By | 2016-09-12T08:19:04+00:00 June 9th, 2015|Decorating|Comments Off on Interior Design 101: The Rule of Three