The Ideal Dimensions for a Loose Heart Cut Diamond


A heart cut diamond is a statement piece. It’s an unmistakable symbol of love and devotion, and a unique diamond that can’t be found in just any jewelry store.

Because it is an uncommon cut, however, you might not necessarily know what to look for when purchasing your loose heart cut diamond. What makes an “ideal” heart cut? What’s the proper depth of the diamond, or the best length to width ratio? What does diamond fluorescence mean and how does it affect the color?  What carat size best shows off the shape of the heart cut?

Here are the core characteristics to consider if you want to ensure you’re getting the best value for your investment:

Heart Cut Diamond Carat Weight

One major factor to consider when searching for the most brilliant diamond is carat weight. The main appeal of the heart cut is its shape, and for this reason, heart shaped diamonds less than 0.50 carats may not be a good choice. In many cases, diamonds that are less than 0.50 carats are simply too small to really see the shape. This is especially true if the diamond is set in prongs.

The most popular carat weight of a heart cut diamond is one carat, which is big enough to show off the unique shape. This is especially true if you have a heart shaped diamond with an ideal cut.  

Heart Cut Diamond Carat Weight

Heart Diamond Cut

The cut of any diamond is important to understand, since the cut of a diamond will directly affect how light interacts with the diamond’s facets. The GIA explains that, “Precise artistry and workmanship are required to fashion a stone so its proportions, symmetry and polish deliver the magnificent return of light only possible in a diamond.” The cut is what accentuates a diamond’s brilliance, fire and scintillation. When shopping for the most unique, brilliant heart cut diamond, cut is certainly essential.


How internal and external light are reflected.


How light dances into all primary colors, when shone through the diamond.


How much a diamond sparkles with an emphasis on its light and dark areas.

Ideal Heart Cut Diamond Dimensions

When grading a diamond’s cut, a jeweler will look at four elements of the cut: table percentage, depth percentage girdle, and culet.

Heart Diamond Table Percentage

The table of the diamond is the uppermost, flat facet of the gem. Diamonds with a larger table return more light through the top of the diamond. They may appear brighter, but will have less fire. To determine the table percentage, divide the width of the table surface by the width of the whole diamond.

Heart Diamond Table Percentage

Heart Diamond Depth Percentage

The depth of the diamond is the distance from the table to the culet (the bottom “point” of the diamond). Depth percentage is calculated by dividing the depth of the diamond by it’s width. The lower the percentage, the larger the diamond will appear from above.

Heart Diamond Depth Percentage

Heart Diamond Girdle

The girdle is the outermost edge of the diamond, running parallel to the table. It can be a single continuous surface (polished or unpolished), or made of small polished facets. The width of the girdle can affect the positive of surrounding facets, thus impacting brilliance, fire, and scintillation.

Girdle’s are described in terms of width, from “Extremely Thin” to “Extremely Thick.”

Heart Diamond Girdle

Heart Diamond Culet

The culet is the bottom of the diamond. For most diamond cuts, the culet is a single point which appears naked to the visible eye when the diamond is viewed from above. If the culet is off-center or too large, it may appear as an imperfection within the diamond. As such, the better the cut, the smaller the surface area of the culet.

Heart Diamond Culet

Heart Diamond Length & Width Ratio

Another key characteristic of the diamond cut is the length to width ratio. For some cuts, such as the round or princess diamond, this ratio must be exact for it to be an “ideal” cut. Heart shaped diamonds, however, have a little more leeway. While it’s commonly agreed that the ideal length and width ration for heart shapes is 1.00, if your are planning on having the diamond set in a pendant, a narrow cut (1.05 to 1.15) may be best for brilliance. For a solitaire ring, a more robust ratio (0.85 to 1.00) may be more appropriate.

At the end of the day, the cut ratio of the heart diamond you have your heart set on is a matter of personal preference.

Heart Diamond Length & Width Ratio |

Color & Heart Diamonds

Which color works best for heart diamonds can be slightly subjective. In fact, many people prefer color grades of G to H, which are slightly warmer than the colorless diamond grades of D to F. So while certain color grades are considered ideal, it’s important not to forget that your own taste is the best deciding factor.

A diamond’s color grade is not the only characteristic to consider. Fluorescence is something to pay close attention to as well. It can sometimes change the color of a diamond, affecting its value.

According to the GIA, “Fluorescence is the glow you sometimes see when an object emits visible light. This can cause them to emit a bluish light or more rarely, a yellow or orangey light.”

Color & Heart Diamonds |

Heart Diamond Clarity

Similar to color characteristics of heart cut diamonds, your personal preference over clarity plays a big role. Some people may be ok with a few inclusions, while others prefer none. Of course, the clarity will also affect the value of the heart cut diamond.

Finding the perfect heart cut diamond can be an exciting experience, and it’s easier with a little knowledge. From symmetry to the 4Cs, knowing more about the ideal dimensions of any diamond is a necessary part of making sure you get the best value for your investment.

Heart Diamond Clarity |
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