Comprehensive Diamond Size Guide | Find Your Perfect Size

Round cut: All the rage

The history of the round cut diamond is a little bit different than other shapes. To begin with, it took an enormous amount of time and diamond cutting to get to the result we know. It was basically invented by experts in the attempt to find the diamond cut with the most facets and the most shine.

Today nearly every round diamond is cut in the brilliant style, meaning they have more facets and angles. There used to be other types where diamonds were cut with larger more open facets, like the old mine way. Well, you can still find them in the market but brilliant round diamonds are a lot more common. Rounds are the most popular shape for all type of jewellery, not only engagement rings. Well-cut round diamonds boast mathematical precision in their faceting (the individual polished surfaces). This perfection creates optimal light return and intense sparkle, resulting in gems that impress in all lighting conditions. That means they shine the most! The round brilliant cut diamond has 58 facets divided among its crown (top), girdle (widest part) and pavilion (base). (gráfico)

Shop now

Round Diamond Size Chart
Size	Caret Weight	Size	Caret Weight	Size	Caret Weight
0.8 mm.	0.0025 ct.	4.5 mm.	0.36 ct.	9.1 mm.	3.00 ct.
1 mm.	0.005 ct.	4.75 mm.	0.44 ct.	9.5 mm.	3.35 ct.
1.1 mm.	0.0067 ct.	5.0 mm.	0.50 ct.	9.75 mm.	3.50 ct.
1.2 mm.	0.009 ct.	5.25 mm.	0.56 ct.	10 mm.	3.87 ct.
1.25 mm.	0.01 ct.	5.5 mm.	0.66 ct.	10.25 mm.	4.00 ct.
1.3 mm.	0.01 ct.	5.75 mm.	0.75 ct.	10.5 mm.	4.41 ct.
1.5 mm.	0.015 ct.	6 mm.	0.84 ct.	10.75 mm.	4.50 ct.
1.75 mm.	0.02 ct.	6.25 mm.	0.93 ct.	11 mm.	5.00 ct.
1.8 mm.	0.025 ct.	6.5 mm.	1.00 ct.	11.25 mm.	5.49 ct.
2 mm.	0.03 ct.	6.8 mm.	1.25 ct.	11.5 mm.	5.85 ct.
2.2 mm.	0.04 ct.	7 mm.	1.30 ct.	12 mm.	6.84 ct.
2.5 mm.	0.06 ct.	7.3 mm.	1.50 ct.	12.25 mm.	7.26 ct.
2.75 mm.	0.08 ct.	7.5 mm.	1.67 ct.	12.5 mm.	7.36 ct.
3 mm.	0.10 ct.	7.75 mm.	1.75 ct.	12.75 mm.	7.52 ct.
3.25 mm.	0.14 ct.	8 mm.	2.00 ct.	13 mm.	8.51 ct.
3.5 mm.	0.17 ct.	8.25 mm.	2.11 ct.	13.5 mm.	9.53 ct.
3.75 mm.	0.21 ct.	8.5 mm.	2.43 ct.	14 mm.	10.49 ct.
4 mm.	0.25 ct.	8.7 mm.	2.50 ct.	15 mm.	12.89 ct.
4.25 mm.	0.28 ct.	9 mm.	2.75 ct.	16 mm.	16.06 ct.

Oval cut: Diamond ellipses

The first known oval cut diamond was recorded in 1304. Paintings featuring diamonds during the medieval and Renaissance were dark, though as the centuries moved on, cutters learned how to facet diamonds to increase their scintillation. It obviously has been getting better and popular with time, and their light show is comparable to a round brilliant diamond.

In fact, oval-cut appeared in the modern brilliant cut in 1957, first accomplished by the russian diamond cutter Lazare Kaplan, a guy born in a family of diamond cutters that spent years searching for a mathematical formula to find the “ideal cut”. Ok, sure it can look pretty similar to round cut diamonds, but read this: The shape of the diamond directly impacts price and face-up size. This means that an oval cut can cost at least 25% less than a round cut of the same weight. Since the oval diamond has a larger surface, it will actually appear bigger than a round. And it also flatters the hand; it can make one's fingers look longer and thinner, like those of a pianist. Win win!

Shop now

Oval Diamond Size Chart
MM SIZE	Carat Weight	MM SIZE	Carat Weight
3.6x2.7 mm.	0.10 ct.	10x8 mm.	2.50 ct.
4x3 mm.	0.15 ct.	10.5x8.5 mm.	2.88 ct.
4.5x3.5 mm.	0.20 ct.	12x8 mm.	3.00 ct.
5x3 mm.	0.25 ct.	12x8.5 mm.	3.50 ct.
5.5x3.5 mm.	0.33 ct.	11x9 mm.	3.85 ct.
5x4 mm.	0.35 ct.	12.5x8.5 mm.	4.00 ct.
6x4 mm.	0.50 ct.	12.75x8.5 mm.	4.50 ct.
6x5 mm.	0.61 ct.	12x10 mm.	5.00 ct.
6.5x4.5 mm.	0.65 ct.	14x10 mm.	5.81 ct.
7x5 mm.	0.75 ct.	13x11 mm.	6.05 ct.
7.7x5.7 mm.	1.00 ct.	14x12 mm.	8.21 ct.
8x6 mm.	1.25 ct.	15x12 mm.	8.76 ct.
9x6 mm.	1.41 ct.	16x12 mm.	9.32 ct.
8.5x6.5 mm.	1.50 ct.	16x14 mm.	11.88 ct.
9x6.5 mm.	1.75 ct.	18x13 mm.	12.86 ct.
9x7 mm.	2.00 ct.	20x15 mm.	14.96 ct.

Pear cut: The fancy fruit

The pear shaped diamond setting can be described as the result of putting marquise shaped diamonds and oval shaped diamonds into a blender. The result is a more brilliant and magical diamond cut that resembles a teardrop; a slightly flatter and larger bottom with the rest of the diamond coming to a skinny point at the top of the stone.

Back in 1475, there was this Flemish diamond cutter (Belgian would be these days) named Lodewyk van Bercken who had just invented a diamond-polishing wheel who would change the industry forever. This pioneering polishing wheel enabled him to place facets onto a diamond rough with complete symmetry, thereby creating a trail for the later development of complex diamond cuts. In that same year, he invented the world's first pear shaped diamond. And since then, over 500 years ago, cutters have labored hard to determine the ideal ratio of length to width for pear shaped diamonds to optimize their sparkle factor. The number of facets however, have remained the same since their beginning. Van Bercken established his pear cut diamond with 58 facets and it hasn’t veered from that standard all these centuries later. The pear shape’s body allows the wearer the option of pointing it up or down. Its faceting often masks inclusions, and those found near the point tend to be less visible. Pear shapes can be wide or elongated, with longer pear shapes providing a slimming effect on fingers.

Shop now

Pear Diamond Size Chart
MM SIZE	Carat Weight	MM SIZE	Carat Weight
3x2 mm.	0.13 ct.	12x7 mm.	3.12 ct.
4x2.5 mm.	0.18 ct.	13x8 mm.	3.40 ct.
4x3 mm.	0.21 ct.	12x9 mm.	3.50 ct.
5x3 mm.	0.25 ct.	14x8 mm.	4.00 ct.
5x4 mm.	0.35 ct.	13x9 mm.	4.11 ct.
6x4 mm.	0.50 ct.	14x9 mm.	4.25 ct.
6.5x4.5 mm.	0.60 ct.	14.5x9 mm.	4.50 ct.
7x5 mm.	0.75 ct.	15x9 mm.	5.00 ct.
7.5x5.5 mm.	0.85 ct.	14x10 mm.	5.41 ct.
7.7x5.7 mm.	1.00 ct.	13x11 mm.	5.65 ct.
8x6 mm.	1.25 ct.	15x10 mm.	5.75 ct.
8.5x6.5 mm.	1.50 ct.	16x9 mm.	5.86 ct.
10x6 mm.	1.75 ct.	16x10 mm.	6.27 ct.
8.7x6.7 mm.	1.80 ct.	17x10 mm.	6.46 ct.
9x7 mm.	2.00 ct.	15x11 mm.	7.36 ct.
10x8 mm.	2.50 ct.	18x11 mm.	8.14 ct.
11x7.50 mm.	2.61 ct.	16x12 mm.	8.99 ct.
11x8 mm.	2.70 ct.	18x12 mm.	9.35 ct.
12x8 mm.	3.00 ct.	18x13 mm.	10.21 ct.

Princess cut: What woman want

Are you familiar with the expression “Customer is always right”? This statement applies perfectly to princess cut diamonds because it was basically created way back in the 14th Century after interviewing women for several years, trying to find out what they really wanted.

Princess cut is famous for its incredible shine despite its square cut. Plus, the cut uses up to 80% of the rough diamond, meaning that is not only gorgeous but also more friendly with the enviroment. At least more than other diamond shapes. But the princess cut we know, the perfectly square diamond, (although is still available in rectangular shape) was not achieved until early 1960 and it is also not quite clear about when it started being called that way; some say it was sometime during de 60´s but the truth is that by 1980 the popularity of the princess cut diamond was high indeed.

Shop now

Princess Diamond Size Chart
Size	Caret Weight	Size	Caret Weight
1.5 mm.	0.015 ct.	6.5 mm.	1.50 ct.
1.75 mm.	0.03 ct.	6.75 mm.	1.75 ct.
2 mm.	0.06 ct.	7 mm.	2.00 ct.
2.25 mm.	0.08 ct.	7.25 mm.	2.01 ct.
2.5 mm.	0.10 ct.	7.5 mm.	2.50 ct.
2.75 mm.	0.13 ct.	7.75 mm.	2.74 ct.
3 mm.	0.18 ct.	8 mm.	3.00 ct.
3.25 mm.	0.25 ct.	8.25 mm.	3.24 ct.
3.5 mm.	0.29 ct.	8.5 mm.	3.50 ct.
3.75 mm.	0.31 ct.	8.75 mm.	4.00 ct.
4 mm.	0.39 ct.	9.25 mm.	4.50 ct.
4.25 mm.	0.44 ct.	9.5 mm.	5.00 ct.
4.5 mm.	0.50 ct.	9.75 mm.	5.36 ct.
4.75 mm.	0.64 ct.	10 mm.	5.62 ct.
5 mm.	0.75 ct.	10.25 mm.	5.76 ct.
5.25 mm.	0.90 ct.	10.5 mm.	5.99 ct.
5.5 mm.	1.00 ct.	11 mm.	7.44 ct.
5.75 mm.	1.11 ct.	11.5 mm.	9.44 ct.
6 mm.	1.25 ct.	12 mm.	9.52 ct.
6.25 mm.	1.39 ct.

Cushion cut: The sparkling pillow

The cushion cut diamond dates back to the 19th century but somehow it´s called “the old new classic” meaning it has the power of coexisting in trend both in the past and in the present time.

Similar to the princess cut, this diamond features a relatively square shape still can come in a multitude of ratios, making it either square or rectangular. Its trademark anyhow are the rounded corners of the stone, the ones that make it look like an actual cushion. The patterns obtained in the cushion cut design allow more light to flow through the stone and return to the eye. There are people saying that this shape is one of the most brilliant of all diamond cuts because the angles of light streaming into each facet work wonders in obscuring tiny imperfections inside the stone. What is actually true is that cushion cut might be the best choice while working with coloured diamonds because its countless reflections work together to enlighten the stone´s natural colour.

Shop now

Cushion Diamond Size Chart
MM SIZE	Carat Weight
3.25 mm.	0.25 ct.
4.2 mm.	0.40 ct.
4.9 mm.	0.50 ct.
5.25 mm.	0.75 ct.
5.5 mm.	1.00 ct.
6 mm.	1.25 ct.
6.5 mm.	1.50 ct.
6.75 mm.	1.75 ct.
7 mm.	2.00 ct.
7.5 mm.	2.50 ct.
8 mm.	3.00 ct.
8.5 mm.	3.50 ct.
9 mm.	4.00 ct.
9.3 mm.	4.50 ct.
9.5 mm.	5.00 ct.
10 mm.	5.62 ct.
11 mm.	7.44 ct.
12 mm.	9.52 ct.
13 mm.	12.66 ct.

Emerald cut: Art Deco in your hand

Believe it or not, not everyone prefers the flashy brilliance of a round diamond. There are tons of people going for something more subtle and sophisticated, like the beloved emerald cut. Emerald diamond cuts were some of the very first diamond cuts in the world.

You know, as diamonds are the hardest substance on earth, polishing and cutting were nearly impossible in ancient times with no technology. It wasn't until the 13th century that diamonds were worn in cut form, when gem cutters discovered that diamonds could be polished and cut using their own dust. The actual term “emerald cut” was not used until the 1920s when it became more popular. The rise of art deco, where clean lines and symmetry were admired, inspired the emerald cut trend. Since then, emerald cuts have remained one of the most popular choices for engagement rings and other jewelry pieces. As we just stated above with cushion cut diamonds, the emerald cut has also long been employed to enhance the richness of colored gemstones. The large table and deep pavilion prominent in an emerald-cut stone draw the light and the eye inward, deepening and intensifying the color to mesmerizing effect.

Shop now

Emerald Diamond Size Chart
MM SIZE	Carat Weight	MM SIZE	Carat Weight
3x2 mm.	0.10 ct.	9.3x7.5 mm.	3.00 ct.
3.5x2 mm.	0.12 ct.	9.5x7.5 mm.	3.21 ct.
4x2 mm.	0.15 ct.	9.75x7.7 mm.	3.50 ct.
4x3 mm.	0.20 ct.	9.9x7.8 mm.	3.79 ct.
4.30x3 mm.	0.25 ct.	10x8 mm.	4.00 ct.
5x3 mm.	0.29 ct.	10.5x8.5 mm.	4.50 ct.
5.5x3.5 mm.	0.46 ct.	11x9 mm.	5.00 ct.
6x4 mm.	0.50 ct.	12x8 mm.	5.34 ct.
6.5x4.5 mm.	0.75 ct.	12x10 mm.	6.00 ct.
6.7x4.5 mm.	0.88 ct.	14x8 mm.	6.25 ct.
7x5 mm.	1.00 ct.	14x9 mm.	6.38 ct.
7.3x5.3 mm.	1.25 ct.	14x10 mm.	8.48 ct.
7.5x5.5 mm.	1.50 ct.	13x11 mm.	9.13 ct.
8x6 mm.	1.75 ct.	14x12 mm.	11.26 ct.
8.5x6.5 mm.	2.00 ct.	16x12 mm.	14.22 ct.
9x7 mm.	2.50 ct.

Heart Cut: All you need is love

Do you treasure every princess Disney movie? Do you know the words to every Michael Bubble´s song? Then this is definitely your diamond cut. I mean, what shouts "love" more than a heart?

The heart shape goes way back in history. In 1463, an early heart-shaped diamond cut made its debut during private exchanges between the Duke of Milan, named Galeazzo Maria Sforza, and the Duke’s confidante Nicodemo, where a heart-shaped diamond was discussed. About a hundred years later, in the early 1560s, Mary, Queen of Scots gifted Elizabeth I of England a gold ring containing a heart-cut diamond, despite their rivalry for the English throne. Historians believe that during this period, the diamond heart became associated with symbols of love and admiration. The modern heart has 59 expertly sculpted facets. It is often one of the most popular ways for a cutter to transform a diamond crystal with small inclusions into a flawless, symmetric and sparkling jewel.

Shop now

Heart Diamond Size Chart
MM SIZE	Carat Weight	MM SIZE	Carat Weight
3.5 mm.	0.18 ct.	8 mm.	2.00 ct.
4 mm.	0.25 ct.	8.5 mm.	2.50 ct.
4.25 mm.	0.28 ct.	9 mm.	3.00 ct.
4.5 mm.	0.34 ct.	10 mm.	3.50 ct.
4.75 mm.	0.38 ct.	10.5 mm.	4.00 ct.
5 mm.	0.50 ct.	11 mm.	4.50 ct.
5.5 mm.	0.61 ct.	11.5 mm.	5.00 ct.
6 mm.	0.75 ct.	12 mm.	5.66 ct.
6.25 mm.	0.83 ct.	13 mm.	7.88 ct.
6.5 mm.	1.00 ct.	14 mm.	9.38 ct.
7 mm.	1.25 ct.	15 mm.	10.79 ct.
7.5 mm.	1.50 ct.	16 mm.	13.27 ct.
7.7 mm.	1.75 ct.	18 mm.	15.33 ct.

Marquise cut: The French Kiss

So you like romance, right? There was a french king, let´s say Louis XV, who despite being married to Marie Antoinette also had several mistresses, a common practice with royalty, then (and now). One of his favorite lovers was Madame du Pompadour.

He was so in love with her that he gave her a place in his court as the Marquise de Pompadour and declared her lips were the most perfect ones he had ever seen. Being that said, he commissioned a royal jeweler to create a design and shape of diamond that looked most like them and voilá! Marquise Cut was born. The marquise cut diamond goes by many nicknames, including the football cut, boat cut, eye cut, or the navette cut. Is a variant of round and pear shaped diamonds, and like the oval is a perfect complement to long, slender fingers. The marquise cut's elongated body can also make its appearance larger than its actual carat weight. This gorgeous cut effortlessly fits into the most complex design layout. Marquise cut then may be the diamond cut for someone who enjoy admiring a stone that appears much larger than it actually is—and has a super-romantic history behind.

Shop now

Marquise Diamond Size Chart
MM SIZE	Carat Weight	MM SIZE	Carat Weight
3x1.5 mm.	0.025 ct.	10x5 mm.	1.00 ct.
3.5x1.75 mm.	0.065 ct.	11x5.5 mm.	1.25 ct.
3.5x2 mm.	0.07 ct.	11.5x6 mm.	1.33 ct.
4x2 mm.	0.10 ct.	12x6 mm.	1.50 ct.
3.75x1.75 mm.	0.11 ct.	12.5x6.25 mm.	1.75 ct.
4.25x2.25 mm.	0.12 ct.	13x6.5 mm.	2.00 ct.
5x2.5 mm.	0.14 ct.	14x7 mm.	2.50 ct.
5.5x2.75 mm.	0.16 ct.	15x7 mm.	3.00 ct.
5.5x3 mm.	0.18 ct.	15x7.5 mm.	3.25 ct.
5x3 mm.	0.20 ct.	15x8 mm.	3.50 ct.
6.5x3 mm.	0.23 ct.	16x8 mm.	3.86 ct.
6x3 mm.	0.25 ct.	16.5x8.25 mm.	4.00 ct.
7x3 mm.	0.30 ct.	16.75x8.5 mm.	4.50 ct.
7.5x3.5 mm.	0.33 ct.	17x8.5 mm.	5.00 ct.
7x4 mm.	0.34 ct.	17.5x10 mm.	5.50 ct.
8x4 mm.	0.50 ct.	20x8 mm.	7.08 ct.
8.75x4.25 mm.	0.70 ct.	20x10 mm.	7.94 ct.
9x4.5 mm.	0.75 ct.	20x11 mm.	9.50 ct.
9.5x4.7 mm.	0.85 ct.

Radiant cut: Shinny 70´s

This cut has a creator with a first and last name and surprisingly enough it didn't happen that far in time. It was invented by Henry Grossbard in 1977 because he was trying to combine the best aspects of the round cut with the best aspects of the emerald cut and since then is considered to be one of the shiniest cuts of diamonds because of its 70-facet cut.

A beautifully symmetrical, non-traditional cut, the radiant cut combines the brilliance of a round and the purity of an emerald cut. Trimmed corners give it versatility among all kinds of jewelry, especially engagement rings. So, to sum up, radiant cut might be the best choice for buyers who like the emerald cut shape, but still want something with the brilliance of a round.

Shop now

Radiant Diamond Size Chart
MM SIZE	Carat Weight	MM SIZE	Carat Weight
4.3x3 mm.	0.25 ct.	10x8 mm.	3.50 ct.
4.5x3.5 mm.	0.34 ct.	10.2x8.2 mm.	4.00 ct.
6x3 mm.	0.41 ct.	10.5x8.5 mm.	4.50 ct.
6x4 mm.	0.50 ct.	11x9 mm.	5.00 ct.
6.5x4.5 mm.	0.75 ct.	12x9 mm.	6.06 ct.
7x5 mm.	1.00 ct.	11.5x10 mm.	6.45 ct.
7.3x5.5 mm.	1.25 ct.	13x9 mm.	6.54 ct.
7.5x5.8 mm.	1.50 ct.	13.2x9.2 mm.	6.79 ct.
8x6 mm.	1.75 ct.	14x10 mm.	8.47 ct.
8.2x6.2 mm.	2.00 ct.	13x11 mm.	9.33 ct.
8.5x6.5 mm.	2.25 ct.	13.5x11.5 mm.	10.19 ct.
9x7 mm.	2.50 ct.	15x11 mm.	11.48 ct.
9.5x7.5 mm.	3.00 ct.	14x12 mm.	12.14 ct.
10x7 mm.	3.31 ct.	16x12 mm.	14.22 ct.

Asscher cut: The X shape

As we´ve been learning, most diamond shapes are named from what they look like: round brilliant, pear, oval, or heart shape. But one stand-out diamond shape is both sophisticated and bears a fascinating historical appellation that has nothing to do with its shape.

It’s called the Asscher Cut, named after legendary diamond cutter Joseph Asscher, founder of I J Asscher Diamond Company. At the time of its invention, he had a patent put on his unique design and it was actually the first time in history that someone patented a diamond cut. Its patent was extended until World War II, and it protected Asscher’s elegant facet design from being replicated by other diamantieres. Yes it reminds us of the emerald cut, but Asscher cuts are not that elongated and rectangular but a clip-cornered squarer version of that popular cut. Looking straight on the Asscher cut diamond, it reveals an X shape made by converging equidistant facets centering toward the culet on the bottom (pavilion side) center of the stone. By viewing the stone from its side profile, you notice that the crown is higher than that of other diamond shapes. Asscher cuts give off a timeless effect with their vintage and unique designs; they have a clean balance, visual appeal, and can reflect clarity inclusions and color. The step cut emphasizes the clarity of the diamond, and it is ideal for showcasing higher clarity diamonds.

Shop now

Asscher Diamond Size Chart
MM SIZE	Carat Weight
4 mm.	0.39 ct.
4.5 mm.	0.50 ct.
5 mm.	0.75 ct.
5.5 mm.	1.00 ct.
6 mm.	1.25 ct.
6.5 mm.	1.50 ct.
7 mm.	2.00 ct.
7.5 mm.	2.50 ct.
8 mm.	3.00 ct.
8.5 mm.	3.50 ct.
9 mm.	4.12 ct.
9.5 mm.	5.09 ct.
10 mm.	5.62 ct.
11 mm.	7.44 ct.
12 mm.	9.52 ct.
13 mm.	12.66 ct.

Country/region

Round cut: All the rage

Diamond Size Chart