9.88ct Oval (18.19×12.2×7.15) vs 10ct Oval (18.96×12.55×7.48)

Diamond size comparison

Actual size is set for screen Change
Actual size of 9.88ct Oval diamond
Actual size
sample image
vs.
Actual size of 10ct Oval diamond
Actual size
sample image
9.88 ct Oval (18.19×12.2×7.15mm) 10 ct Oval (18.96×12.55×7.48mm)
Cutting style
Modified brilliant
Modified brilliant
Weight
9.88 ct
10 ct
Measurements
18.19×12.2×7.15 mm
18.96×12.55×7.48 mm
Total depth
58.6% too shallow!
59.6% OK
L/W ratio
1.49
1.51
Face-up size
Adequate
Inadequate
 
This diamond LOOKS its weight!
This diamond is a SPREAD CUT!
Actual diamond size
Actual diamond size
Before purchasing a diamond, one should make sure it looks its weight. It's important to understand that carat weight does not equal face-up size.

Two diamonds of exactly the same weight (and shape) can vary quite considerably in face-up size. This depends on the proportions of the cut (e.g., deep cuts will face up smaller).

Here you can see the actual sizes of 9.88ct Oval (18.19×12.2×7.15mm) and 10ct Oval (18.96×12.55×7.48mm) as they would appear on a ring and finger.

Adjust the ring and finger size to get an idea of how these stones would look on your finger.
Settings
Ring: Skin tone:
Ring width: 3.0 mm
Saved...
Left finger image
Ring on a left finger
9.88ct Oval on a left ring
64 mm
Right finger image
Ring on a right finger
10ct Oval on a right ring
Your settings
Ring
Gold
Skin tone
Light
Ring diameter
16.9 mm
Ring width
3.0 mm
Finger length
64 mm
Saved...
Ring diameter: 16.9 mm
USA UK Asia EU1 EU2
9.88ct Oval side view Side view of ring
vs
10ct Oval side view Side view of ring
Actual size is set for screen Change
Face-up area
181.97 mm²  (±5%)
195.12 mm²  (±5%)
Face-up area is a measure of the size of the diamond when viewed from the top (as set in a ring).

It tells you how big the diamond is at the girdle plane. It's important for a diamond to have sufficient face-up size for its carat weight.
Face-up size outline
Face-up size outline
9.88ct Oval (18.19×12.2×7.15mm)
10ct Oval (18.96×12.55×7.48mm)
Difference: 13.15mm² (7%)
10 carat Oval (18.96×12.55×7.48mm) has approx. 7% more face-up area than 9.88 carat Oval (18.19×12.2×7.15mm).
Face-up area per carat
18.42 mm²/ct
19.51 mm²/ct
To learn about the accuracy of these numbers, click here.


Quick Buying Guide

Diamond prices vary greatly as they depend on the combination of unique characteristics (4Cs - Cut, Color, Clarity, and Carat). For best value, it's important to choose the combination that will reduce the price without having a negative impact on appearance.

Each shape has its own recommended balance of qualities that will give you the most bang for your buck. Below is a quick buying guide to give you an idea, but for more detailed explanation, please see the complete buying guides for the respective diamonds (links below).
9.88ct Oval (18.19×12.2×7.15mm)
10ct Oval (18.96×12.55×7.48mm)
Price (best value)
Min. clarity
SI or better
SI or better
Min. color (platinum setting)
I+
I+
Min. color (yellow gold setting)
J+
J+
Depth percentage
59 - 65%
59 - 65%
Table percentage
53 - 62%
53 - 62%
Length-to-width ratio
1.25 - 1.65
1.25 - 1.65
Min. polish/symmetry
Good or better
Good or better
 Detailed buying guide

Additional Info

9.88ct Oval (18.19×12.2×7.15mm)
10ct Oval (18.96×12.55×7.48mm)
Face-up size
Normal for 9.88 carat Oval
Too large for 10 carat Oval
Facets
usually 58
usually 58
Length
18.19 mm
18.96 mm
Width
12.2 mm
12.55 mm
Depth
7.15 mm
7.48 mm
Gram weight
1.98 g (0.0697 ounces)
2 g (0.0705 ounces)
Points
988 pts
1000 pts
Volume
561.36 mm³
568.18 mm³


Compare diamonds

Choose diamonds to compare:
 
× ×
carat vs. length* width* depth*
× ×
 
* Optional

Depth percentage for 9.88 carat Oval (18.19×12.2×7.15mm)

Depth percentage of Oval cut is the ratio of the total depth (measured from table to culet) to its width. The total depth percentage of this diamond is 58.6%, which is too shallow!. (Recommended depth percentage for Ovals is between 59% and 65%)

Depth percentage for ovals is calculated with the following formula:
Depth % = (total depth ÷ width) × 100

9.88 carat Oval (18.19×12.2×7.15mm) depth %:
Total depth: 7.15 mm
Width = 12.2 mm
Depth % = (7.15 ÷ 12.2 ) × 100 = 58.6%

Depth percentage for 10 carat Oval (18.96×12.55×7.48mm)

Depth percentage of Oval cut is the ratio of the total depth (measured from table to culet) to its width. The total depth percentage of this diamond is 59.6%, which is OK. (Recommended depth percentage for Ovals is between 59% and 65%)

Depth percentage for ovals is calculated with the following formula:
Depth % = (total depth ÷ width) × 100

10 carat Oval (18.96×12.55×7.48mm) depth %:
Total depth: 7.48 mm
Width = 12.55 mm
Depth % = (7.48 ÷ 12.55 ) × 100 = 59.6%

About Depth Percentage
Depth percentage is one of the most important measurements as it plays a critical role in diamond's appearance. If a diamond is cut too deep or too shallow, light leaks out, making the stone less brilliant and fiery. Deep cuts also add hidden weight.

Diamonds that fall out of recommended depth range are generally less desirable and usually best to be avoided.


Face-up size evaluation for 9.88 carat Oval (18.19×12.2×7.15mm)

The face-up size of this 9.88 carat Oval (18.19×12.2×7.15mm) is within the normal range for 9.88ct diamonds of this shape. Compared to 9.88ct Oval reference diamond (see below), this diamond is of adequate size when viewed from the top. In short, all is OK, this diamond looks its weight.

The importance of face-up size
Diamonds are sold by weight (carats), but it's important to understand that weight doesn't equally translate into physical size, especially spread. Two diamonds of the same carat weight can vary greatly in spread, meaning that one diamond can appear larger than the other, even though they weight exactly the same.

Proper face-up size should play an important role when buying a diamond. When a diamond is set in a ring, your eyes will only see the face-up area, so you should make sure it's of adequate size. Adequate size also indicates a good cut, meaning better light performance. For example, if given a choice between a poorly cut 9.9 carat Oval with less sparkle and the same face-up size as a well cut 9.4ct Oval, which one would you choose?

The bottom line: A diamond must look its weight. This one does. Thumbs up.

9.88 carat Oval reference diamond
Since there are no specific ideal proportions defined for Oval cuts, an estimation formula is used to calculate the Oval reference diamond.
Parameters:
Weight: 9.88ct
Depth: 61%
L/W ratio: 1.5
 
Calculated values:
Length: 17.43 mm
Width: 11.62 mm
Depth: 7.09 mm
*Est. face-up area: 166.08 mm²
Note: Oval diamonds with face-up area of within 9% lower and 12% higher than reference Oval diamond area are considered to be of adequate face-up size.
* Estimated Face-up area: Face-up area of Oval cuts is only an estimation (±5%). Due to uniqueness of each stone, it's impossible to accurately calculate face-up area given only a diamond's measurements.

Face-up size evaluation for 10 carat Oval (18.96×12.55×7.48mm)

The face-up size of this 10 carat Oval (18.96×12.55×7.48mm) is out of normal range for 10ct diamonds of this shape. Compared to 10 carat Oval reference diamond, this diamond appears too big when viewed from the top. You might think that's a good thing, however, it's not. This is a so called spread cut.

A spread cut is a diamond that is cut to maximize spread instead of optimal light performance. If compared from above, it would look larger than a well cut 10ct Oval. This is not a good thing. Spread cuts are typically too shallow, which allows light to leak out of the stone resulting in less light being reflected back to the viewer's eye.

Spread cuts usually look lifeless and flat, and can sometimes exhibit a fish-eye effect. They may also come with an extremely thin girdle which can easily chip.

The bottom line: Spread cuts generally lack the brilliance and perfection that is expected of a beautiful diamond. Don't be fooled into thinking that you're getting a larger diamond for the money. This could be a rather flat, boring stone.

10 carat Oval reference diamond
Since there are no specific ideal proportions defined for Oval cuts, an estimation formula is used to calculate the Oval reference diamond.
Parameters:
Weight: 10ct
Depth: 61%
L/W ratio: 1.5
 
Calculated values:
Length: 17.49 mm
Width: 11.66 mm
Depth: 7.11 mm
*Est. face-up area: 167.23 mm²
Note: Oval diamonds with face-up area of within 9% lower and 12% higher than reference Oval diamond area are considered to be of adequate face-up size.
* Estimated Face-up area: Face-up area of Oval cuts is only an estimation (±5%). Due to uniqueness of each stone, it's impossible to accurately calculate face-up area given only a diamond's measurements.

Face-up Area per Carat

Face-up area per carat is calculated by dividing face-up area of the diamond with its carat weight. It tells you how many square millimeters of the top surface area a diamond is showing or would show for 1 carat weight. This can be useful when comparing stones of similar weights as it tells you how much spread per carat you will get.

Note: Face-up size does not linearly grow with carat weight, which means the heavier the stone, the smaller its face-up area per carat (e.g., 1ct stone will have higher face-up area per carat than 2ct stone).

Face-up area per carat for 9.88ct Oval (18.19×12.2×7.15mm):
Top surface area = 181.97 mm²
Weight = 9.88ct

Face-up area per carat = 181.97 ÷ 9.88 = 18.42mm²/ct

Face-up area per carat for 10ct Oval (18.96×12.55×7.48mm):
Top surface area = 195.12 mm²
Weight = 10ct

Face-up area per carat = 195.12 ÷ 10 = 19.51mm²/ct

Enter your screen size (diagonal)

My screen size is  inches



Actual size is currently adjusted to screen.

If your screen (phone, tablet, or monitor) is not in diagonal, then the actual size of a diamond, ring and finger will not be shown correctly.