Introduction
When choosing an engagement ring, one thing that many people are concerned about is the size of the diamond.
Carat is a unit of weight and does not necessarily correspond to apparent diameter.
In this article, we will compare diamonds ranging from 0.3 to 3 carats using a table and images of how they will look when worn , and explain the key points to consider when choosing the right size for an engagement ring.
table of contents
1. What is the relationship between diamond carat and size?
When choosing an engagement ring, the biggest concern for many people is the size of the diamond.
Many people tend to think that "carat" means size, but in fact carat is a unit of weight and does not exactly correspond to the apparent diameter.
For example, even if a diamond is the same 1 carat, its diameter and impression can change depending on the depth and shape of the cut.
Therefore, rather than choosing based on the carat weight alone, it is important to consider the diameter size and how it will look on your finger.
2. Size chart for 0.3 to 3 carats (round brilliant)
We have compiled a table showing approximate carat weights and diameter sizes for the "round brilliant cut," which is particularly popular for engagement rings.
| carat | Diameter (mm) | General impression |
|---|---|---|
| 0.3ct | Approximately 4.3mm | Small and discreet. Easy to use for everyday use. |
| 0.5ct | Approximately 5.1mm | A popular standard size in Japan |
| 1.0ct | Approximately 6.5mm | The classic engagement ring size. A perfect balance of presence and elegance. |
| 1.5ct | Approximately 7.4mm | A size that enhances the sense of luxury |
| 2.0ct | Approximately 8.2 mm | A special large diamond |
| 3.0ct | Approximately 9.4mm | A striking presence. A rare and eye-catching size. |
3. Wearing image (comparison of 0.3 to 3 carats)
This image shows a comparison of round diamonds ranging from 0.3ct to 3ct, placed on the same finger. You can see the difference in size at a glance, making it easier to imagine how they will look on your finger.
0.3-0.5ct : Subtly sparkling, small and suitable for everyday use.
1-1.5ct : A classic engagement ring. A good balance of elegance and glamour.
2-3ct : Outstanding presence. Recommended for those who want to stand out from the crowd.
4. Carat size guidelines for engagement rings
4.1 Japanese average
In Japan, the average size of an engagement ring is said to be between 0.2 and 0.4 carats .
However, in recent years, more and more people are choosing "0.5ct to 1ct" stones, and there is a trend towards wanting a more solid presence on the hand.
4.2 Overseas trends
In America and Europe, stones over 1 carat are the norm.
With the spread of ethical, affordable lab-grown diamonds, more and more couples in Japan are choosing large diamonds.
5. Key points for choosing carat
5.1 Choose the size that fits your fingers and hand size
For delicate hands, 0.5 to 1ct is a good balance.
For larger hands → Even 1ct or more will fit naturally
5.2 Compare your budget and price
Natural diamonds: 1 carat, starting from around 1 million yen
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Lab-grown diamonds (artificial diamonds): You can choose from as little as 400,000 yen for the same 1ct diamond.
5.3 Be aware of the difference in appearance depending on the shape
Diamond shapes such as oval, marquise and emerald cut tend to appear larger than a round cut diamond of the same carat weight.
Summary | It's important to see it for yourself
It is difficult to judge the size of a diamond by numbers alone; you can only know the "comfortable size" by wearing it on your finger.
At DIALLURE,
Abundant samples ranging from 0.5 to 3 carats
You can compare both natural and lab-grown diamonds
Try out a variety of shapes
It has the following characteristics:
If you are interested, please come and see us at our showroom.
Frequently Asked Questions (FAQ)
Q1.Are the carat and size (diameter) of a diamond the same thing?
A1. No, carat is a unit of weight, not size itself.
Even if the diamond is the same 1 carat, its diameter and appearance will change depending on the depth and shape of the cut.
Q2.What is the most popular diamond size for engagement rings?
A2.Until now, most people in Japan have chosen 0.3 to 0.5 carats, but in recent years, the number of people choosing 1 carat has been increasing. Overseas, diamonds over 1 carat are the norm, and with the advent of lab-grown diamonds, it has become easier to choose large diamonds.
Q3. How much difference is there in appearance between 0.5 carat and 1 carat?
A 0.5 carat diamond has a diameter of approximately 5.1 mm, while a 1 carat diamond has a diameter of approximately 6.5 mm, which means the difference in presence is even greater than the numbers suggest. When compared on the actual finger, a 1 carat diamond is a size that stands out as being "gorgeous, like an engagement ring."
