1.8ct Trillion (9.41×9.41×3.76) vs 1ct Round (6.5×6.5×3.92)
Diamond size comparison
Actual size is set for screen
Change
sample image
|
vs. |
sample image
|
|||||||||
1.8 ct Trillion (9.41×9.41×3.76mm) | 1 ct Round (6.5×6.5×3.92mm) |
Cutting style
Modified brilliant
Brilliant
Weight
1.8 ct
1 ct
Measurements
9.41×9.41×3.76 mm
6.5×6.5×3.92 mm
L/W ratio
1
1
Face-up size
Adequate
Adequate
This diamond LOOKS its weight!
This diamond LOOKS its weight!
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 1.8ct Trillion (9.41×9.41×3.76mm) and 1ct Round (6.5×6.5×3.92mm) 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. To choose different diamonds or to change diamond parameters click here.
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 1.8ct Trillion (9.41×9.41×3.76mm) and 1ct Round (6.5×6.5×3.92mm) 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. To choose different diamonds or to change diamond parameters click here.
Settings
Ring:
Skin tone:
Ring width: 3.0 mm
Saved...
|
![]() ![]() ![]() |
64 mm |
![]() ![]() ![]() |
|
||||||||||||||||
|
||||||||||||||||||||
|
|
|
Actual size is set for screen
Change
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.
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](images/diamonds/trillion_outline_purple_bg.png)
![Face-up size outline](images/diamonds/round_outline_gray_bg.png)
1.8ct Trillion (9.41×9.41×3.76mm) | |
1ct Round (6.5×6.5×3.92mm) | |
Difference: 21.72mm² (65%) |
1.8 carat Trillion (9.41×9.41×3.76mm) has approx. 65% more face-up area than 1 carat Round (6.5×6.5×3.92mm).
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).
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).
1.8ct Trillion (9.41×9.41×3.76mm)
1ct Round (6.5×6.5×3.92mm)
Min. clarity
SI or better
SI or better
Min. color (platinum setting)
H+
J+
Min. color (yellow gold setting)
J+
K+
Depth percentage
32 - 48%
58 - 62.5%
Table percentage
50 - 70%
53 - 58%
Length-to-width ratio
1.00 - 1.10
1.00 - 1.02
Min. polish/symmetry
Good or better
Good or better
Additional Info
1.8ct Trillion (9.41×9.41×3.76mm)
1ct Round (6.5×6.5×3.92mm)
Face-up size
Normal for 1.8 carat Trillion
Normal for 1 carat Round
Facets
Between 31 - 50
58 (57 if no culet)
Length
9.41 mm
6.5 mm
Width
9.41 mm
6.5 mm
Depth
3.76 mm
3.92 mm
Gram weight
0.36 g (0.0127 ounces)
0.2 g (0.0071 ounces)
Points
180 pts
100 pts
Volume
102.27 mm³
56.82 mm³
Compare diamonds
Choose diamonds to compare:
Popular comparisons:
- 1.8ct Trillion (9.41x9.41x3.76) vs. 2ct Trillion (9.75x9.75x3.9)
- 1.8ct Trillion (9.41x9.41x3.76) vs. 0.5ct Emerald (5.31x3.93x2.55)
- 1.8ct Trillion (9.41x9.41x3.76) vs. 1.37ct Round (7.15x7.17x4.38)
- 1.8ct Trillion (9.41x9.41x3.76) vs. 1.77ct Emerald (8x6x3.9)
- 1.8ct Trillion (9.41x9.41x3.76) vs. 1.5ct Round (7.44x7.44x4.49)
- 1.8ct Trillion (9.41x9.41x3.76) vs. 1.8ct Round (7.91x7.91x4.77)
- 1.8ct Trillion (9.41x9.41x3.76) vs. 1.8ct Pear (11.01x6.63x4.04)
- 1.75ct Trillion (9.32x9.32x3.73) vs. 2ct Trillion (9.75x9.75x3.9)
- 1.8ct Trillion (10.06x10.06x4.02) vs. 2.2ct Round (8.45x8.45x5.1)
Depth percentage for 1.8 carat Trillion (9.41×9.41×3.76mm)
Depth percentage of Trillion cut is the ratio of the total depth (measured from table to culet)
to its width. The total depth percentage of this diamond
is 40%, which is OK.
(Recommended depth percentage for Trillions is between 32% and
48%)
Depth percentage for trillions is calculated with the following formula:
Depth percentage for trillions is calculated with the following formula:
Depth % = (total depth ÷ width) × 100
1.8 carat
Trillion
(9.41×9.41×3.76mm) depth %:
Total depth: 3.76 mm
Width = 9.41 mm
Width = 9.41 mm
Depth % = (3.76 ÷ 9.41 ) × 100 = 40%
Depth percentage for 1 carat Round (6.5×6.5×3.92mm)
Depth percentage of Round cut is the ratio of the total depth (measured from table to culet)
to its average diameter. The total depth percentage of this diamond
is 60.3%, which is OK.
(Recommended depth percentage for Rounds is between 58% and
62.5%)
Depth percentage for rounds is calculated with the following formula:
Depth percentage for rounds is calculated with the following formula:
Depth % = (total depth ÷ average diameter) × 100
1 carat
Round
(6.5×6.5×3.92mm) depth %:
Total depth: 3.92 mm
Average diameter = (6.5 + 6.5) ÷ 2 = 6.5 mm
Average diameter = (6.5 + 6.5) ÷ 2 = 6.5 mm
Depth % = (3.92 ÷ 6.5 ) × 100 = 60.3%
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.
Diamonds that fall out of recommended depth range are generally less desirable and usually best to be avoided.
Face-up size evaluation for 1.8 carat Trillion (9.41×9.41×3.76mm)
The face-up size of this 1.8 carat Trillion
(9.41×9.41×3.76mm) is within the normal range for
1.8ct diamonds of this shape.
Compared to 1.8ct
Trillion 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.
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 1.8 carat Trillion with less sparkle and the same face-up size as a well cut 1.6ct Trillion, which one would you choose?
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 1.8 carat Trillion with less sparkle and the same face-up size as a well cut 1.6ct Trillion, which one would you choose?
The bottom line:
A diamond must look its weight. This one does. Thumbs up.
1.8 carat Trillion reference diamond
Since there are no specific ideal proportions defined for Trillion cuts,
an estimation formula is used to calculate the Trillion reference diamond.
|
|
Note: Trillion diamonds with face-up area of within 13% lower
and 16% higher than reference Trillion diamond area
are considered to be of adequate face-up size.
* Estimated Face-up area: Face-up area of Trillion cuts
is only an estimation (±9%). Due to uniqueness of each stone,
it's impossible to accurately calculate face-up area given only a diamond's measurements.
To learn more about diamond size evaluation, click here.
Face-up size evaluation for 1 carat Round (6.5×6.5×3.92mm)
The face-up size of this 1 carat Round
(6.5×6.5×3.92mm) is within the normal range for
1ct diamonds of this shape.
Compared to 1ct
Round 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.
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. Would you want a poorly cut 1 carat diamond that is less sparkly and has the same face-up size as an ideal cut 0.9 carat? Probably not.
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. Would you want a poorly cut 1 carat diamond that is less sparkly and has the same face-up size as an ideal cut 0.9 carat? Probably not.
The bottom line:
A diamond must look its weight. This one does. Thumbs up.
1 carat Round reference diamond
1ct Round reference diamond is calculated from the following ideal proportions:
|
|
Note: Round diamonds with face-up area of within 5% lower
and 3% higher than reference Round diamond area
are considered to be of adequate face-up size.
To learn more about diamond size evaluation, click here.
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 1.8ct Trillion (9.41×9.41×3.76mm):
Top surface area = 54.9 mm²
Weight = 1.8ct
Face-up area per carat = 54.9 ÷ 1.8 = 30.5mm²/ct
Weight = 1.8ct
Face-up area per carat = 54.9 ÷ 1.8 = 30.5mm²/ct
Face-up area per carat
for 1ct Round (6.5×6.5×3.92mm):
Top surface area = 33.18 mm²
Weight = 1ct
Face-up area per carat = 33.18 ÷ 1 = 33.18mm²/ct
Weight = 1ct
Face-up area per carat = 33.18 ÷ 1 = 33.18mm²/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.
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.