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Arrange your visitDiamond Education · Buying Guide
Oval Buying Guide
The oval diamond is a popular shape that is elongated with gently rounded edges, resembling an oval or egg shape when viewed from above. The oval cut is a modified brilliant cut, meaning it has a similar faceting pattern to the round brilliant, but with an elongated outline.
Cut
One common characteristic of oval diamonds is the presence of a "bowtie" effect, which is a dark area that appears in the centre of the diamond when viewed from certain angles. This contrast is affected by cut, lighting and viewing position, including light blocked by the observer. Its presence alone does not diagnose a poor cut; judge whether it remains distracting as the stone moves.
The aim is to achieve an oval diamond with minimal bow tie.
Standard GIA reports do not assign ovals the overall cut grade used for round brilliants. IGI offers fancy-shape cut grading, and separate light-performance reports may be available. Check the actual document and assess the stone in motion. We compare individual ovals for their outline, contrast and light performance before presenting a shortlist. The examples below show features to look for.
GoodMinimal bow tie, even brilliance, crisp shoulders
AvoidPronounced bow tie, light leakage, uneven shape
Colour
The characteristics of an oval tend to showcase colour more prominently than a like-for-like round diamond. It's for this reason we hope to stick in the colourless D–E–F range.
Recommended · D to F
Ratio
The length to width ratio is a measure of how elongated or round an oval diamond appears. It is determined by dividing the length of the diamond by its width. A higher ratio indicates a more elongated shape, while a lower ratio indicates a more round shape.
The ideal ratio for an oval in our opinion, is between 1.4 to 1.47.
Closer to 1.3 is shorter and fatter. Above 1.5 is longer and skinnier. You can have 3 diamonds all 2ct, but can have very different shapes for all three. Please bear in mind, the optimal ratio can vary depending on personal preferences.
Clarity
Given an oval cut diamond has a fairly large open surface area, it's easier to spot imperfections than say a round diamond. For this reason it's best to find ovals with imperfections away from the centre/table.
Recommended · SI1 to VS2
Difficulty in Repeatability
Ovals like many other fancy shapes are tricky. It's tricky for retailers, customers and even the ones who manufacture them. Below is an array of 1ct ovals, cut by the same factory, all to the same spec. But as you can see only 3 came out looking sharp with a blended in bowtie. The rest, not so much. To put it simply, you need a large sample size and cherry pick the absolute best. That principle applies to all fancy shapes. Some jewellers don't bother because it takes too long, and it does. One search takes an hour easily. But we only sell what we're proud of and nothing less.
Oval diamond size chart
What an oval's measurements mean in carat weight, and the reverse. Every row from 0.30ct up is the median of real certified ovals in our own inventory, with the sample size beside it; the smaller sizes come from our diamond supplier's book, because we don't stock loose stones that small and it would be dishonest to quote inventory we don't have.
| Length × width | Carat weight | Typical range | Based on |
|---|---|---|---|
| 2.0 × 1.4 mm | 0.019 ct | — | Calculated |
| 2.5 × 1.8 mm | 0.036 ct | — | Calculated |
| 3.0 × 2.2 mm | 0.063 ct | — | Supplier measurement |
| 3.5 × 2.5 mm | 0.09 ct | — | Supplier measurement |
| 3.6 × 2.7 mm | 0.10 ct | — | Supplier measurement |
| 4.0 × 3.0 mm | 0.15 ct | — | Supplier measurement |
| 4.5 × 3.5 mm | 0.20 ct | — | Supplier measurement |
| 4.8 × 3.3 mm | 0.21 ct | — | Supplier measurement |
| 5.0 × 3.7 mm | 0.30 ct | 0.30–0.31 ct | 115 stones |
| 5.5 × 4.0 mm | 0.34 ct | 0.30–0.40 ct | 680 stones |
| 6.0 × 4.3 mm | 0.46 ct | 0.40–0.51 ct | 890 stones |
| 6.3 × 4.5 mm | 0.50 ct | 0.47–0.53 ct | 486 stones |
| 6.5 × 4.6 mm | 0.54 ct | 0.50–0.61 ct | 1,693 stones |
| 7.0 × 5.0 mm | 0.71 ct | 0.62–1.00 ct | 1,569 stones |
| 7.5 × 5.3 mm | 0.91 ct | 0.77–1.07 ct | 2,855 stones |
| 7.9 × 5.6 mm | 1.00 ct | 0.92–1.20 ct | 948 stones |
| 8.0 × 5.8 mm | 1.06 ct | 1.00–1.12 ct | 17,339 stones |
| 9.0 × 6.5 mm | 1.52 ct | 1.42–1.59 ct | 26,636 stones |
| 9.9 × 7.1 mm | 2.00 ct | 1.86–2.44 ct | 400 stones |
| 10.0 × 7.2 mm | 2.04 ct | 1.81–2.14 ct | 13,801 stones |
| 11.0 × 7.8 mm | 2.59 ct | 2.42–3.07 ct | 8,834 stones |
| 11.4 × 8.1 mm | 3.00 ct | 2.94–4.06 ct | 292 stones |
| 12.0 × 8.4 mm | 3.34 ct | 3.01–4.06 ct | 8,013 stones |
| 13.0 × 9.0 mm | 4.06 ct | 3.92–4.53 ct | 6,093 stones |
| 14.0 × 9.8 mm | 5.10 ct | 5.00–6.09 ct | 1,356 stones |
| 15.0 × 10.4 mm | 6.31 ct | 6.02–7.52 ct | 673 stones |
| 16.0 × 11.3 mm | 8.02 ct | 7.04–9.03 ct | 464 stones |
| 17.0 × 11.9 mm | 9.15 ct | 8.58–10.22 ct | 280 stones |
| 18.0 × 12.5 mm | 10.58 ct | 10.02–11.59 ct | 145 stones |
Rows from 0.30 ct up are the median of our own GIA and IGI certified stones, with the sample size shown and the typical range being the middle 80% of that bucket. Smaller sizes come from our diamond supplier's own book where it carries the shape, and are calculated from the trade weight formula where it does not. Covers 2.0 mm to 18.0 mm. Snapshot 2026-08-30.
Length and width give an indicative weight range. Depth, girdle thickness and other proportions also affect weight, so this table is an estimate. Use the individual grading report or a measured loose-stone weight for an exact figure. For every other shape, and a converter that works in both directions, see the full diamond size chart.
How much does an oval diamond cost?
Choose a carat weight to see what a natural and a lab-grown oval diamond cost today, or enter your budget to see the size it buys. Each figure is the typical price of the oval diamonds available through us at the grade shown under the results, worked out every night; follow its link to see the real stones.
1 ct oval · Natural
about A$6,799
Typical price · based on 156 diamonds available through us
Listed now, at or under this price
1 ct oval · Lab-grown
about A$1,570
Typical price · based on 137 diamonds available through us
Listed now, at or under this price
At this size, lab-grown costs about 75% less than natural.
Natural: E–F colour, VS2 clarity, excellent cut for rounds. Lab-grown: E colour, VS1 clarity, ideal cut for rounds. GST included.
Put it in an engagement ringTypical prices of the diamonds available through us, updated 4 November 2026. See every shape and size in our diamond price guide.
Compare other shapes
Oval is one of three elongated brilliant cuts. If you're choosing between them, read the Pear Buying Guide or the Marquise Buying Guide. For a single-page side-by-side across all ten shapes, see our Diamond Shape Comparison. Or explore our oval engagement rings when you're ready to choose a setting.
Common questions
What is the bow-tie in an oval diamond?
A bow tie is a dark contrast pattern affected by cut, lighting and viewing position, including light blocked by the observer. Judge whether it remains distracting as the stone moves. Read the actual report, then assess appearance in motion under more than one light source.Do oval cuts look bigger than round?
Yes — an oval diamond has approximately 10% more surface area per carat than a round brilliant of the same weight. A 1.00ct oval measures about 7.9 × 5.6 mm, giving it noticeably more finger presence than a 1.00ct round at 6.4 mm across. This face-up spread is a key reason many buyers choose oval.Which oval length-to-width ratio is best?
The ideal ratio for an oval is between 1.40 and 1.47. Closer to 1.3 the stone reads shorter and fatter; above 1.5 it looks longer and skinnier. Three ovals all at 1.00ct can look strikingly different depending on ratio — always view the actual proportions, not just the carat number.Does oval flatter shorter fingers?
Yes — the elongated outline of an oval visually stretches the finger, making shorter fingers appear longer and slimmer. This is one of the reasons oval sits second only to round in engagement-ring popularity. Ratios between 1.40 and 1.47 give the most flattering elongation without looking stretched.