Size guides › Oval
Oval diamonds
Oval diamond size chart
A round's sparkle in a longer outline that flatters the finger. An oval is a brilliant cut stretched into an ellipse. It keeps much of a round's sparkle, looks bigger for its weight, and makes the finger look longer and slimmer.
Free. Your photo stays on your phone — it's never uploaded.
Every oval size, drawn to scale
From 0.25 to 3 carats, on a millimeter grid. Tap a size to jump to it.
| Carat | Size (mm) | Looks like a round of | Covers of a size 6 finger |
|---|---|---|---|
| 0.25 ct | 4.99 × 3.56 mm | 0.28 ct | 20% |
| 0.5 ct | 6.28 × 4.49 mm | 0.56 ct | 25% |
| 0.75 ct | 7.19 × 5.14 mm | 0.84 ct | 29% |
| 1 ct | 7.91 × 5.65 mm | 1.12 ct | 32% |
| 1.25 ct | 8.53 × 6.09 mm | 1.40 ct | 34% |
| 1.5 ct | 9.06 × 6.47 mm | 1.68 ct | 37% |
| 2 ct | 9.97 × 7.12 mm | 2.25 ct | 40% |
| 2.5 ct | 10.74 × 7.67 mm | 2.81 ct | 43% |
| 3 ct | 11.41 × 8.15 mm | 3.37 ct | 46% |
Typical proportions. Real stones vary by a few tenths of a millimeter — the certificate gives the exact size.
What to know about oval diamonds
Watch for the bow-tie
Many ovals show a dark band across the middle, shaped like a bow-tie, where light leaks out of the stone. A faint one is normal; a strong one is worth avoiding. Only photos or video of the actual stone will show it.
Choose a ratio you like
Most ovals for sale run between about 1.30 and 1.50 long-to-wide. Lower reads fuller and rounder; higher reads longer and slimmer.
It can sit either way
Usually set running along the finger. An east–west setting turns it across, which covers more of the finger's width.
Length-to-width ratio
Two ovals of the same weight can look quite different. These three all weigh 1 ct; only the ratio changes — from 7.6 mm long at 1.30 : 1 to 8.3 mm at 1.50 : 1. It's a matter of taste, not quality.
Oval vs round
The dashed line is a 1 ct round. A 1 ct oval covers about 8% more area from above.
Size by size
Every oval weight, answered
0.25 carat oval
How big is a 0.25 carat oval diamond?
About 5.0 × 3.6 mm, and it looks about as big as a 0.28 ct round. Laid on a US dime (17.91 mm), it would cover about a quarter of the coin's width lengthwise and a fifth of it across.
Small and delicate
A quarter carat reads as a bright point of sparkle rather than a statement. It's a lovely size for minimalist and stacking rings and for anyone who wants something that sits close and never catches, and it leaves room in the budget for a better cut or color. As an oval, it looks about 8% bigger from above than a round of the same weight, so it delivers more of this size's presence for the money.
Ask for the head size
Ready-made east–west head starts above this size, so ask for it made at 5×3.6 mm. The other styles come ready-made for a stone this size.
Want it to look bigger?
A halo of small diamonds around it takes the face-up width from 3.56 mm to about 4.9 mm — 38% wider — for much less than a bigger center stone would cost.
The same size in other shapes
To cover the same area from above you'd need about 0.28 ct in a round, 0.33 ct in a cushion and 0.32 ct in a princess.
Settings
- Made to orderSolitaire, halo, three stone, bezel and cathedral — the ready-made heads we could find are for round stones, so ask for one made at 5×3.6 mm.
- Made to orderEast–west — the smallest ready-made head is 5 mm, so ask for one made at 5×3.6 mm to hold it snugly.
Shop a 0.25 ct oval: Blue Nile · Blue Nile, lab-grown · With Clarity · Rare Carat
Blue Nile opens already narrowed to 0.23–0.27 ct at a length-to-width ratio of 1.35 to 1.45 — the range of weights a stone this size can be — so the first page of results is this size rather than every oval they carry. It also asks for a well-cut oval's depth (57–67%) and table (52–62%).
0.5 carat oval
How big is a 0.5 carat oval diamond?
About 6.3 × 4.5 mm, and it looks about as big as a 0.56 ct round. Laid on a US dime (17.91 mm), it would cover about a third of the coin's width lengthwise and a quarter of it across.
Petite and practical
Half a carat is a classic petite size: noticeable without being showy, comfortable for everyday wear, and easy to set low so it doesn't snag on gloves or knitwear. As an oval, it looks about 8% bigger from above than a round of the same weight, so it delivers more of this size's presence for the money.
Consider 0.45 ct
Prices tend to step up at round weights like 0.5 ct. A 0.45 ct oval measures about 6.06 × 4.33 mm — only 0.15 mm narrower, with 7% less area on top. That's very hard to see on a hand.
Want it to look bigger?
A halo of small diamonds around it takes the face-up width from 4.49 mm to about 6.2 mm — 38% wider — for much less than a bigger center stone would cost.
The same size in other shapes
To cover the same area from above you'd need about 0.56 ct in a round, 0.67 ct in a cushion and 0.63 ct in a princess.
Settings
- Comes pre-madeEast–west — ask for a 6.3×4.5 mm head.
- Made to orderSolitaire, halo, three stone, bezel and cathedral — the ready-made heads we could find are for round stones, so ask for one made at 6.3×4.5 mm.
Shop a 0.5 ct oval: Blue Nile · Blue Nile, lab-grown · With Clarity · Rare Carat
Blue Nile opens already narrowed to 0.46–0.53 ct at a length-to-width ratio of 1.35 to 1.45 — the range of weights a stone this size can be — so the first page of results is this size rather than every oval they carry. It also asks for a well-cut oval's depth (57–67%) and table (52–62%).
0.75 carat oval
How big is a 0.75 carat oval diamond?
About 7.2 × 5.1 mm, and it looks about as big as a 0.84 ct round. Laid on a US dime (17.91 mm), it would cover about two-fifths of the coin's width lengthwise and a quarter of it across.
Just under the milestone
Three-quarters of a carat gives a good share of the look of a one-carat stone, and on a slim finger the difference can be hard to see. It's a sensible size if the budget is better spent on cut quality or the setting. As an oval, it looks about 8% bigger from above than a round of the same weight, so it delivers more of this size's presence for the money.
Want it to look bigger?
A halo of small diamonds around it takes the face-up width from 5.14 mm to about 7.1 mm — 38% wider — for much less than a bigger center stone would cost.
The same size in other shapes
To cover the same area from above you'd need about 0.84 ct in a round, 1.00 ct in a cushion and 0.95 ct in a princess.
Settings
- Comes pre-madeEast–west — ask for a 7.2×5.1 mm head.
- Made to orderSolitaire, halo, three stone, bezel and cathedral — the ready-made heads we could find are for round stones, so ask for one made at 7.2×5.1 mm.
Shop a 0.75 ct oval: Blue Nile · Blue Nile, lab-grown · With Clarity · Rare Carat
Blue Nile opens already narrowed to 0.70–0.80 ct at a length-to-width ratio of 1.35 to 1.45 — the range of weights a stone this size can be — so the first page of results is this size rather than every oval they carry. It also asks for a well-cut oval's depth (57–67%) and table (52–62%).
1 carat oval
How big is a 1 carat oval diamond?
About 7.9 × 5.7 mm, and it looks about as big as a 1.12 ct round. Laid on a US dime (17.91 mm), it would cover about two-fifths of the coin's width lengthwise and a third of it across.
The milestone size
One carat is the size many people picture when they think of an engagement ring. It's clearly a center stone without being heavy, and it suits almost every setting style. As an oval, it looks about 8% bigger from above than a round of the same weight, so it delivers more of this size's presence for the money.
Consider 0.9 ct
Prices tend to step up at round weights like 1 ct. A 0.9 ct oval measures about 7.64 × 5.46 mm — only 0.20 mm narrower, with 7% less area on top. That's very hard to see on a hand.
Turned east–west
Set across the finger instead of along it, its 7.91 mm length spans 45% of a size 6 finger instead of 32%. A modern look that reads wider.
The same size in other shapes
To cover the same area from above you'd need about 1.12 ct in a round, 1.33 ct in a cushion and 1.26 ct in a princess.
Settings
- Comes pre-madeEast–west — ask for a 7.9×5.7 mm head.
- Made to orderSolitaire, halo, three stone, bezel and cathedral — the ready-made heads we could find are for round stones, so ask for one made at 7.9×5.7 mm.
Shop a 1 ct oval: Blue Nile · Blue Nile, lab-grown · With Clarity · Rare Carat
Blue Nile opens already narrowed to 0.93–1.07 ct at a length-to-width ratio of 1.35 to 1.45 — the range of weights a stone this size can be — so the first page of results is this size rather than every oval they carry. It also asks for a well-cut oval's depth (57–67%) and table (52–62%).
1.25 carat oval
How big is a 1.25 carat oval diamond?
About 8.5 × 6.1 mm, and it looks about as big as a 1.40 ct round. Laid on a US dime (17.91 mm), it would cover about half of the coin's width lengthwise and a third of it across.
A step past one carat
A quarter carat over the milestone. It reads as noticeably substantial on most hands while still sitting comfortably in standard settings, and it avoids the round-number weights where prices tend to jump. As an oval, it looks about 8% bigger from above than a round of the same weight, so it delivers more of this size's presence for the money.
Turned east–west
Set across the finger instead of along it, its 8.53 mm length spans 48% of a size 6 finger instead of 34%. A modern look that reads wider.
The same size in other shapes
To cover the same area from above you'd need about 1.40 ct in a round, 1.66 ct in a cushion and 1.58 ct in a princess.
Settings
- Comes pre-madeEast–west — ask for a 8.5×6.1 mm head.
- Made to orderSolitaire, halo, three stone, bezel and cathedral — the ready-made heads we could find are for round stones, so ask for one made at 8.5×6.1 mm.
Shop a 1.25 ct oval: Blue Nile · Blue Nile, lab-grown · With Clarity · Rare Carat
Blue Nile opens already narrowed to 1.16–1.34 ct at a length-to-width ratio of 1.35 to 1.45 — the range of weights a stone this size can be — so the first page of results is this size rather than every oval they carry. It also asks for a well-cut oval's depth (57–67%) and table (52–62%).
1.5 carat oval
How big is a 1.5 carat oval diamond?
About 9.1 × 6.5 mm, and it looks about as big as a 1.68 ct round. Laid on a US dime (17.91 mm), it would cover about half of the coin's width lengthwise and a third of it across.
A clear statement
At a carat and a half, the stone is the first thing people notice about the ring. It's still easy to wear every day, but cut quality starts to show more, because there's more stone to see. As an oval, it looks about 8% bigger from above than a round of the same weight, so it delivers more of this size's presence for the money.
Consider 1.4 ct
Prices tend to step up at round weights like 1.5 ct. A 1.4 ct oval measures about 8.85 × 6.32 mm — only 0.15 mm narrower, with 4% less area on top. That's very hard to see on a hand.
Where ready-made heads stop
This is the first weight past the ready-made east–west head. A setting made to order takes it in any style — ask for a 9.1×6.5 mm head rather than buying a ready-made mounting.
Turned east–west
Set across the finger instead of along it, its 9.06 mm length spans 51% of a size 6 finger instead of 37%. A modern look that reads wider.
The same size in other shapes
To cover the same area from above you'd need about 1.68 ct in a round, 2.00 ct in a cushion and 1.89 ct in a princess.
Settings
- Made to orderEast–west — the largest ready-made head is 9 mm, so ask for one made at 9.1×6.5 mm.
- Made to orderSolitaire, halo, three stone, bezel and cathedral — the ready-made heads we could find are for round stones, so ask for one made at 9.1×6.5 mm.
Shop a 1.5 ct oval: Blue Nile · Blue Nile, lab-grown · With Clarity · Rare Carat
Blue Nile opens already narrowed to 1.40–1.60 ct at a length-to-width ratio of 1.35 to 1.45 — the range of weights a stone this size can be — so the first page of results is this size rather than every oval they carry. It also asks for a well-cut oval's depth (57–67%) and table (52–62%).
2 carat oval
How big is a 2 carat oval diamond?
About 10.0 × 7.1 mm, and it looks about as big as a 2.25 ct round. Laid on a US dime (17.91 mm), it would cover about three-fifths of the coin's width lengthwise and two-fifths of it across.
A large stone
Two carats is big on most hands and is seen from across a room. At this size clarity and color are easier to judge by eye, and a secure head matters more, so ask how it's set. As an oval, it looks about 8% bigger from above than a round of the same weight, so it delivers more of this size's presence for the money.
Consider 1.9 ct
Prices tend to step up at round weights like 2 ct. A 1.9 ct oval measures about 9.80 × 7.00 mm — only 0.12 mm narrower, with 3% less area on top. That's very hard to see on a hand.
Turned east–west
Set across the finger instead of along it, its 9.97 mm length spans 56% of a size 6 finger instead of 40%. A modern look that reads wider.
The same size in other shapes
To cover the same area from above you'd need about 2.25 ct in a round, 2.66 ct in a cushion and 2.52 ct in a princess.
Settings
- Made to orderEast–west — the largest ready-made head is 9 mm, so ask for one made at 10×7.1 mm.
- Made to orderSolitaire, halo, three stone, bezel and cathedral — the ready-made heads we could find are for round stones, so ask for one made at 10×7.1 mm.
Shop a 2 ct oval: Blue Nile · Blue Nile, lab-grown · With Clarity · Rare Carat
Blue Nile opens already narrowed to 1.86–2.14 ct at a length-to-width ratio of 1.35 to 1.45 — the range of weights a stone this size can be — so the first page of results is this size rather than every oval they carry. It also asks for a well-cut oval's depth (57–67%) and table (52–62%).
2.5 carat oval
How big is a 2.5 carat oval diamond?
About 10.7 × 7.7 mm, and it looks about as big as a 2.81 ct round. Laid on a US dime (17.91 mm), it would cover about three-fifths of the coin's width lengthwise and two-fifths of it across.
Very large
Two and a half carats is a very large stone for everyday wear. Setting height starts to matter: a lower head snags less, and a sturdy one protects a stone this valuable. Many owners have it appraised for insurance. As an oval, it looks about 8% bigger from above than a round of the same weight, so it delivers more of this size's presence for the money.
Turned east–west
Set across the finger instead of along it, its 10.74 mm length spans 61% of a size 6 finger instead of 43%. That's a lot of finger; try it on a photo of your own hand first.
The same size in other shapes
To cover the same area from above you'd need about 2.81 ct in a round, 3.33 ct in a cushion and 3.15 ct in a princess.
Settings
- Made to orderEast–west — the largest ready-made head is 9 mm, so ask for one made at 10.7×7.7 mm.
- Made to orderSolitaire, halo, three stone, bezel and cathedral — the ready-made heads we could find are for round stones, so ask for one made at 10.7×7.7 mm.
Shop a 2.5 ct oval: Blue Nile · Blue Nile, lab-grown · With Clarity · Rare Carat
Blue Nile opens already narrowed to 2.33–2.68 ct at a length-to-width ratio of 1.35 to 1.45 — the range of weights a stone this size can be — so the first page of results is this size rather than every oval they carry. It also asks for a well-cut oval's depth (57–67%) and table (52–62%).
3 carat oval
How big is a 3 carat oval diamond?
About 11.4 × 8.2 mm, and it looks about as big as a 3.37 ct round. Laid on a US dime (17.91 mm), it would cover about two-thirds of the coin's width lengthwise and half of it across.
Dramatic
Three carats is a show-stopping size. It dominates all but the broadest fingers, so seeing it on your own hand before buying matters more here than at any other size. Look for a head made for a stone this size, and insure it. As an oval, it looks about 8% bigger from above than a round of the same weight, so it delivers more of this size's presence for the money.
Consider 2.9 ct
Prices tend to step up at round weights like 3 ct. A 2.9 ct oval measures about 11.29 × 8.06 mm — only 0.09 mm narrower, with 2% less area on top. That's very hard to see on a hand.
Turned east–west
Set across the finger instead of along it, its 11.41 mm length spans 65% of a size 6 finger instead of 46%. That's a lot of finger; try it on a photo of your own hand first.
The same size in other shapes
To cover the same area from above you'd need about 3.37 ct in a round, 3.99 ct in a cushion and 3.78 ct in a princess.
Settings
- Made to orderEast–west — the largest ready-made head is 9 mm, so ask for one made at 11.4×8.2 mm.
- Made to orderSolitaire, halo, three stone, bezel and cathedral — the ready-made heads we could find are for round stones, so ask for one made at 11.4×8.2 mm.
Shop a 3 ct oval: Blue Nile · Blue Nile, lab-grown · With Clarity · Rare Carat
Blue Nile opens already narrowed to 2.79–3.21 ct at a length-to-width ratio of 1.35 to 1.45 — the range of weights a stone this size can be — so the first page of results is this size rather than every oval they carry. It also asks for a well-cut oval's depth (57–67%) and table (52–62%).
We may earn a commission from Blue Nile and Rare Carat, at no extra cost to you. The others pay us nothing. Nothing about you is sent. How this site is funded.
See an oval on your own hand
Pick a size, add a photo of your hand, and see it at its real size — with the fit check built in.
Questions
How big is a 0.25 carat oval diamond?
About 4.99 × 3.56 mm, and it looks about as big as a 0.28 carat round.
How big is a 0.5 carat oval diamond?
About 6.28 × 4.49 mm, and it looks about as big as a 0.56 carat round.
How big is a 0.75 carat oval diamond?
About 7.19 × 5.14 mm, and it looks about as big as a 0.84 carat round.
How big is a 1 carat oval diamond?
About 7.91 × 5.65 mm, and it looks about as big as a 1.12 carat round.
How big is a 1.25 carat oval diamond?
About 8.53 × 6.09 mm, and it looks about as big as a 1.40 carat round.
How big is a 1.5 carat oval diamond?
About 9.06 × 6.47 mm, and it looks about as big as a 1.68 carat round.
How big is a 2 carat oval diamond?
About 9.97 × 7.12 mm, and it looks about as big as a 2.25 carat round.
How big is a 2.5 carat oval diamond?
About 10.74 × 7.67 mm, and it looks about as big as a 2.81 carat round.
How big is a 3 carat oval diamond?
About 11.41 × 8.15 mm, and it looks about as big as a 3.37 carat round.
Do oval diamonds look bigger than round ones?
Yes. At the same weight an oval covers about 8% more area from above than a round.
What is the best length-to-width ratio for an oval?
There's no best — it's taste. Most ovals for sale run between about 1.30 and 1.50 long-to-wide. Lower reads fuller and rounder; higher reads longer and slimmer.
What size setting does an oval diamond need?
Any common style can be made to fit it: ask for a head the size of the stone — about 7.9×5.7 mm for a 1 ct. Ready-made heads are mostly listed for round stones, so for an oval choose a setting made to order.