Its character
Reads larger than a round of equal weight because more of its surface faces up. The trade-off is the bow-tie — a darker band across the centre where light escapes rather than returns. Every oval has one to some degree; on a well-cut stone it is faint enough to miss.
Where the oval cut comes from
Oval stones are old, but the modern oval brilliant is usually credited to Lazare Kaplan, who developed it in the early 1960s by adapting round brilliant faceting to an elongated outline.
Ovals have become one of the most requested shapes for engagement rings in recent years, largely because they look bigger than a round of the same weight and flatter the finger.
How a oval is faceted
An oval usually has 56 to 58 facets arranged much like a round brilliant, stretched along one axis. That gives it similar sparkle, but stretching the pattern changes the angles along the length, and some light escapes through the middle of the stone instead of returning.
The result is the bow-tie: a darker, bow-shaped band across the width. Almost every oval shows one to some degree. On a well-cut stone it is faint and shifts as the stone moves; on a poor one it is solid and distracting.
Oval cut proportions
Ranges most well-cut oval stones fall within. They narrow the field; they do not replace seeing the stone.
| Measure | Typical range | Why it matters |
|---|---|---|
| Table | 53 – 63% | Similar to a round. |
| Depth | 58 – 63% | Deeper stones lose face-up size. |
| Length to width | 1.30 – 1.50 | 1.35 – 1.45 is the most requested range. |
| Girdle | Thin to slightly thick | Uneven girdles distort the outline. |
| Culet | None | |
| Cut grade | Not graded | Neither GIA nor IGI assigns an overall cut grade to this shape, so these are trade ranges rather than a standard. |
What to look for in a oval diamond
The bow-tie is the first thing to check, and no report grades it — it has to be judged on the stone or on video. Ratio is largely a matter of taste: around 1.35 reads classic, 1.5 and above reads slender. Ovals flatter the hand and sit comfortably in a four- or six-prong setting.
- Bow-tie
- No laboratory report mentions the bow-tie, so it has to be checked in a video or in person. Look for a band that flickers rather than one that stays dark.
- Outline
- Both halves should mirror each other, with no flat or bulging sides. The ends should be evenly curved, not pointed or squared off.
- Ratio
- Choose the ratio by eye. The same carat weight looks noticeably different at 1.30 and at 1.50.
- Colour at the ends
- Elongated shapes can show more colour toward their tips. A near-colourless grade or better keeps them looking even.
Setting a oval
Four or six prongs are typical, with six giving more security. East-west settings, where the oval lies across the finger, are a popular modern variation. Ovals also suit halo and three-stone designs.
Oval size by carat weight
Approximate face-up size at a typical oval ratio and depth, drawn to scale. Select a weight to see natural stock in that band.
5 mm. Every silhouette is drawn to this scale, at typical proportions.
- Natural oval diamonds, 0.25–0.49 ct, about 5.1 × 3.6 mm face up
- Natural oval diamonds, 0.50–0.74 ct, about 6.4 × 4.6 mm face up
- Natural oval diamonds, 0.75–0.99 ct, about 7.3 × 5.2 mm face up
- Natural oval diamonds, 1.00–1.49 ct, about 8.0 × 5.7 mm face up
- Natural oval diamonds, 1.50–1.99 ct, about 9.2 × 6.6 mm face up
- Natural oval diamonds, 2.00–2.99 ct, about 10.1 × 7.2 mm face up
- Natural oval diamonds, 3.00 ct and above, about 11.6 × 8.3 mm face up
Diamond carat guide: every shape, price milestones and choosing a weight
Terms used on this page
Each one is defined in full, with what a report prints for it, in the glossary.
- Bow-tie
- A dark band across the centre of an elongated stone, shaped like a bow-tie.
- Brilliant cut
- A faceting style built from triangular and kite-shaped facets radiating from the centre.
- Length-to-width ratio
- The outline's proportions — length divided by width — which decides how a fancy shape reads.
- Spread
- How large a stone looks from above, relative to what its carat weight would suggest.
- Symmetry
- How precisely the facets line up with one another and with the outline.
- Depth %
- The stone's height from table to culet as a percentage of its average diameter.
Oval cut questions
What buyers ask most often before choosing a oval diamond.
What is a bow-tie in an oval diamond?
It is a darker band across the centre of the stone where light escapes instead of returning to the eye. Nearly all ovals have one; the goal is a faint bow-tie that shifts as the stone moves. Grading reports do not assess it.
Does an oval diamond look bigger than a round?
Yes. Because it is elongated and relatively shallow, an oval shows more surface area from above than a round of the same carat weight.
What is the best length-to-width ratio for an oval?
Most buyers choose between 1.35 and 1.45. Below about 1.30 the stone looks nearly round; above 1.50 it looks slender. There is no single correct ratio.