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The Oval Cut Diamond Guide: Does Oval Look Bigger?

The Oval Cut Diamond Guide: Does Oval Look Bigger?

The Oval Cut Diamond Guide: Does Oval Look Bigger?

Posted by Sharif Khan on 14th Jan 2021

oval cut ratio

Key Takeaways:

  • According to Blue Nile and James Allen (two of our favorite online retailers), oval shape diamonds are second in terms of demand in 2019, right next to the traditional round cut diamonds. They serve as beautiful alternatives to round cuts, combining their brilliance with the marquise cut.
  • Oval cut diamonds also have amazing spread and surface size (they look big).
  • In terms of cut, a depth of 55-63% and a table of 52-63% is preferred. Follow our chart below carefully while analyzing the cut of oval shape diamonds.
  • Bow-tie is a necessary topic to be familiar with, and if an oval cut diamond is cut poorly, it will have a large bow-tie effect. Read our guide below and ensure that you have high-quality images/videos of the diamond to assess its bow-tie effect before you place an order.
  • In terms of length-to-width ratio, oval cut diamonds in the range of 1.38%-1.55% are preferred, depending on how roundish or elongated you want the diamond to look. See the chart below for details.
  • In terms of concrete options, if you do not have budget problems and want a stone of investment-grade, look for something like this (option 1). If you desire to maximize carat weight within your budget without compromising the quality, look for an oval cut diamond within this range (option 2). If you do not mind compromising more on the other 3Cs (Cut, Color, Clarity) to maximize the carat weight (as long as the stone is eye-clean), something like this might work for you (option 3). Finally, if you want to compromise on one C to maximize on the other 3Cs, compromise on color while maximizing clarity and cut (option 4).
  • Always buy a diamond that is either graded by the GIA or the AGS.
  • Here is a list of our top vendors for loose diamonds and engagement rings to consider

oval cut proportions

Overview Oval Cut:

Lazare Kaplan created the Oval Cut diamond in the 1960s. These luminous gems are different from your day-to-day diamond shapes as they combine the sparkle of the elongated shape of a marquise cut with the round cut. This shape is cut into a perfectly symmetrical design. Oval cut diamonds possess the fire and brilliance of a round cut diamond, making it an ideal choice for individuals who like round diamonds but desire something distinct.

Like other fancy diamond shapes, preferences of an oval cut diamond also vary by length to width ratios of the cut. A classic oval cut diamond will have its length to width ratio of 1.50 or in the approximate range of 1.36-1.60. This range stretches out the outline enough to be different from a round cut. If the elongation ends up too long, the cut will look similar to a marquise.

The "bow-tie effect" is present in almost all oval, marquis, and pear cut diamonds. Since it carries importance in analyzing an oval cut diamond, please refer to our post on the effect of bow-tie on fancy cut diamonds for more information. In our opinion, a small "bow-tie effect" is a plus for an oval cut diamond. Likewise, please avoid a large "bow-tie effect" because it indicates that the diamond has been cut poorly.

Analyzing Oval Cut:

Hint: Use tools like James Allen's Video 3D 360 Degree 40X Magnified Technology to compare different diamonds and understand the effect of proportions on their cut and shape. It can also help in figuring out what might be the optimal length to width ratio for you.

Depth %
  • Poor/Far: <51 or >75/ 70.9-75
  • Good: 54-56.3 / 66-70.8
  • Very Good: 56-58.1/62-65.9
  • Excellent: 57-61.9
  • Table %
  • Poor/Far: <51 or >72 / 70-72
  • Good: 50 / 66-69
  • Very Good: 52/65
  • Excellent: 53-64
  • Culet
  • Poor/Fair: Very Large/Large
  • Good: Slightly large
  • Very Good: Medium/Very Small
  • Excellent: None
  • Girdle
  • Poor/Fair: Ex. Thin – Ex. Thick
  • Good: Very thin - thick
  • Very Good: Very thin - slightly thick
  • Excellent: Very thin - slightly thick
  • Length to Width Ratio
  • Poor/Fair: >1.66 /1.62-1.66
  • Good: 1.57-1.61
  • Very Good: 1.51-1.56
  • Excellent: 1.36-1.50
  • James Allen

    The chart above serves as a general guideline when evaluating the cut of an oval cut diamond. The length to width ratio of 1.50 is considered the classic cut for an oval cut diamond. Every Petra Gems diamond includes precise measurements and length to width ratio so that our customers can make a rational decision when considering an oval cut diamond.

    oval cut styles

    When it comes to cutting styles, aim for the one in the middle of the above picture (look at the diagram on the GIA report to verify). The styles on the left and right are older versions of the oval cut. However, the one in the middle is the modern brilliant cut. It has 57-58 facets like the round brilliant cut and will give you the best brilliance. 

    Evaluating Color:

    Color is an important C while considering oval cut diamonds. Therefore, prioritize the color after the cut to maximize the brilliance of a diamond. If you do not have significant budget constraints, aim for a D-F color oval cut diamond. However, G is also a great color and is too far off from the colorless range as far as the brilliance of the stone is concerned. H and I are good budget options. The good side to H/I is that the price premium for I and J color grade oval cut diamonds would be lower.

    For more detailed information on the color of an oval cut diamond, use the table below.

    < 0.50 Carat
  • Poor/Far: >M/ L-M
  • Good: I-K
  • Very Good: G-I
  • Excellent: D-G
  • 0.51 – 1.0 Carat
  • Poor/Fair: J-K / >L
  • Good: I
  • Very Good: H
  • Excellent: D-G
  • 1.0 – 2.0 Carat
  • Poor/Fair: >J
  • Good: I/H
  • Very Good: D-G
  • Excellent: D-F
  • >2.0 Carat
  • Poor/Fair: >J
  • Good: H-I
  • Very Good: D-G
  • Excellent: D-F
  • Fluorescence 
  • Poor/Fair: Very Strong/Strong
  • Good: Medium 
  • Very Good: Faint
  • Excellent: None
  • ideal oval cut

    Ideal Length to Width Ratio of 1.45

    Choosing Clarity:

    Choose an oval cut diamond that meets your standards in terms of clarity. Each of our customers has a unique standard for clarity and color. Some want a flawless diamond with a lot of clarity, while others are perfectly comfortable with a slight inclusion if it is not noticeable. The GIA provides excellent help with their clarity grades, which is why you can use it to choose an oval cut diamond that will meet your standards. The chart below serves as a general guide for you to evaluate clarity in oval diamonds.

    < 0.50 Carat
  • Poor/Far: >I1/ I1
  • Good: SI2
  • Very Good: SI1-VS2
  • Excellent: FL-VS1
  • 0.51 – 1.0 Carat
  • Poor/Fair: > I1
  • Good: SI2
  • Very Good: SI1-VS2
  • Excellent: FL-VS1
  • 1.0 – 2.0 Carat
  • Poor/Fair: >I1
  • Good: SI2-SI1
  • Very Good: VS2
  • Excellent: FL-VS1
  • >2.0 Carat
  • Poor/Fair: >I1
  • Good: SI2-SI1
  • Very Good: VS1-VS2
  • Excellent: FL-WS2
  • Prioritizing the 4Cs of Oval Cut:

    Over the last decade, our clients prioritized and compromised on the 4Cs in the following manner:

    Scenario 1: Quality was their primary concern. In this option, they would go for the best of the 4Cs in each given carat weight range. Any diamond above 1 carat, F, VS1, excellent cut, no fluorescence, and GIA/AGS graded would qualify under this scenario. (Such stones are called investment-grade diamonds).

    Scenario 2: Both quality and size were important to them. Under this option, they were willing to compromise on quality slightly to get a bigger diamond. They would go for a 1.5 carat, SI1/VS2, G/H color, very good to excellent cut, up to medium blue fluorescence, and GIA and AGS graded diamond. (These are still high-quality diamonds and would qualify in the investment-grade range).

    Scenario 3: They were willing to compromise on the 3Cs to get a bigger stone as long as the stone was still eye clean and had enough brilliance. Under this option, they would go for, say, a 2-carat diamond that would be I/J color, SI1/SI2 clarity, up to strong blue fluorescence, very good to ideal proportions, and GIA/AGS graded. If you go for this option, make sure that you understand the clarity of the diamond well. Some inclusions, such as large black crystals, should be avoided in low clarity grades as they can be visible in SI2 if present.

    Scenario 4: They would compromise on 1C heavily to maximize the 3Cs. In this case, we recommend that you compromise on the color to maximize the clarity and cut. While you might get a slightly warmer color stone, it will still have fire and sparkle. A good option would be a VVS2, L, medium to strong blue fluorescence with ideal proportions. You can even go for the IGI or the HRD labs in this range since most labs in lower color quality stones are consistent in grading diamonds properly. It is just that they are inconsistent in grading high clarity grades as strictly as the GIA does.

    Budget Options:

    Below is a list of the suggested carat weight, cut, color, and clarity of Oval Cut Diamonds for people on a tight budget.

    Excellent Choice

    • At least 1.0 carats in Weight
    • Very Good to Excellent Polish and Symmetry
    • G or above in color
    • SI1 or above in clarity
    • No Fluorescence
    • Length/width ratios: 1.36 - 1.58

    Very Good Choice:

    • At least 0.90 carats in Weight
    • Good to Excellent Polish and Symmetry
    • H or above in Color
    • SI1 or above in Clarity
    • None, faint or medium blue fluorescence
    • Length/width ratios: 1.36 - 1.58

    Good Choice:

    • At least 0.80 Carats in Weight
    • Good to Very Good Polish and Symmetry
    • I or above in Color
    • SI1 or above in Clarity
    • None, faint or medium blue fluorescence
    • Length/width ratios: 1.36 - 1.58

    Frequently Asked Questions About Oval Cut Diamonds:

    Are oval cut diamonds popular?

    Yes, after round cut diamonds, oval diamonds have emerged as the most popular shapes lately. They are very popular among shoppers who like round diamonds but want something different.

    What about the size of oval cut diamonds compared to round cut diamonds?

    Oval cut diamonds have a big surface size like round diamonds. Since they are more rectangular than square, they might have a bigger surface size in mm than the round ones.

    Do oval cut diamonds sparkle the same as round diamonds?

    While rounds are the king of sparkle and scintillation simply because of the advancement of cutting techniques for round-shape diamonds, ovals are the queen. In our opinion, they stand second and carry similar brilliant faceting to maximize sparkle and fire, combing the best of marquise and round diamonds.

    What about the bow-tie effect in oval cut diamonds?

    Bow-tie is an issue that can affect oval cut diamonds. Ensure that you read our bow-tie guide and consult the diamond dealer about the bow-tie effect before buying the stone. If a stone is cut badly with uneven proportions, it will have a bow-tie—a sign of a poor cut.

    What is the ideal length to width ratio for oval cut diamonds?

    In our opinion, 1.3 to 1.6 is a good range. Depending on how roundish you want the stone to look, anything between this range will do, though our preferred range is 1.38-1.55.

    Check out our loose diamonds page to find recommendations for the best places to buy oval cut diamonds.



    Oval cut diamond ring

    Recommended Proportions - Oval
    Depth% Table Girdle Cullet L/W Ratio
    56-62% 52-63% See Below None