Lozenge Cut Diamond Size Chart - Diamond Weight Calculator

Professional Lozenge Cut Diamond Size Chart

Detailed Carat to MM / MM to Carat Lozenge Cut Diamond Size Chart

In need of a quick and reliable way to see exactly how large a lozenge cut diamond converts to from carat to millimeters? This comprehensive guide delivers both and more. But first, a little about the Lozenge.

The lozenge cut diamond is one of the most distinctive fancy shapes there are in the world. With an instantly recognizable symmetrical rhombus shape featuring four equal sides and pointed corners, it draws inspiration from the diamond symbol in a deck of playing cards.

Popularized during the Art Deco era of the 1920s and 1930s, the lozenge features large trapezoidal step-cut facets that create a a hall of mirrors effect that appeals to one’s innate fascination with geometry. While it may not sparkle as intensely as a brilliant cut, its clean lines and sophistication truly makes it a standout choice for anyone after something unique, refined, and memorable.

Below you will find our very own carat to millimeter conversion charts along with clear, practical recommendations on depth, table, girdle, culet, and length to width ratios.

Lozenge Cut Diamond MM Size Chart / CT Conversion Chart

0.25 - 5.00 cts

LOZENGE CUT DIAMOND CARAT WEIGHT	LOZENGE CUT DIAMOND MM LENGTH	LOZENGE CUT DIAMOND MM WIDTH
0.25	6.65 - 6.90 mm.	3.80 - 4.05 mm.
0.3	7.07 - 7.32 mm.	4.04 - 4.29 mm.
0.4	7.78 - 8.03 mm.	4.44 - 4.69 mm.
0.5	8.38 - 8.63 mm.	4.79 - 5.04 mm.
0.6	8.91 - 9.16 mm.	5.09 - 5.34 mm.
0.7	9.38 - 9.63 mm.	5.35 - 5.60 mm.
0.8	9.80 - 10.05 mm.	5.60 - 5.85 mm.
0.9	10.20 - 10.45 mm.	5.82 - 6.07 mm.
1	10.56 - 10.81 mm.	6.03 - 6.28 mm.
1.2	11.22 - 11.47 mm.	6.41 - 6.66 mm.
1.3	11.53 - 11.78 mm.	6.58 - 6.83 mm.
1.4	11.81 - 12.06 mm.	6.75 - 7.00 mm.
1.5	12.09 - 12.34 mm.	6.90 - 7.15 mm.
1.6	12.35 - 12.60 mm.	7.05 - 7.30 mm.
1.7	12.60 - 12.85 mm.	7.20 - 7.45 mm.
1.8	12.85 - 13.10 mm.	7.34 - 7.59 mm.
1.9	13.08 - 13.33 mm.	7.47 - 7.72 mm.
2	13.30 - 13.55 mm.	7.60 - 7.85 mm.
2.2	13.73 - 13.98 mm.	7.84 - 8.09 mm.
2.5	14.33 - 14.58 mm.	8.18 - 8.43 mm.
2.7	14.70 - 14.95 mm.	8.40 - 8.65 mm.
3	15.23 - 15.48 mm.	8.70 - 8.95 mm.
3.5	16.03 - 16.28 mm.	9.16 - 9.41 mm.
4	16.76 - 17.01 mm.	9.57 - 9.82 mm.
4.5	17.43 - 17.68 mm.	9.96 - 10.21 mm.
5	18.06 - 18.31 mm.	10.31 - 10.56 mm.

Ava Diamonds

How a Lozenge Cut Diamond Looks Like on Hand

One of the best ways to truly appreciate a lozenge cut diamond is to see how it sits on the finger. Its elongated rhombus shape with pointed corners was designed to deliver outstanding finger coverage and a flattering lengthening effect that looks both refined and modern.

The clean geometric lines and optimized spread of the step-cut facets make the stone appear even more impressive in real life than the carat weight alone suggests, so it’s highly recommended to see it in person to truly grasp its beauty. Many people love how it creates a sleek, elegant presence while sparkling subtly from every angle.

The following image demonstrates this by showing what a Lozenge Cut Diamond looks like on hand in a variety of carat weights.

What are the Ideal Proportions of a Lozenge Shaped Diamond?

The lozenge is a classic step-cut fancy shape that demands precise proportions to achieve its signature hall-of-mirrors effect and balanced geometric silhouette. Because of its rhombus outline and large trapezoidal facets, ideal measurements help maximize light reflection while preserving the dramatic elongation and presence that make this cut so special. This, of course, makes it more challenging as well.

What is the Ideal Diamond Depth and Table for the Lozenge Cut?

Achieving the right balance of depth and table percentage is essential for the lozenge cut to display its elegant step-cut brilliance without looking flat or overly deep. The following are the professionally accepted proportion guidelines by experienced gemologists.

	EXCELLENT	VERY GOOD	GOOD
Table - %	58% - 65%	55% - 68%	52% – 72%
Depth - %	61% - 67%	58% - 70%	55% - 73%
Girdle	Thin to Medium	Very Thin to Slightly Thick	Very Thin to Thick
Culet	None to Small	None to Very Small	Small

What is the Ideal Lozenge Diamond Length to Width Ratio?

The length to width ratio is one of the most defining features of the lozenge cut diamond. This shape is intentionally elongated to create sophisticated finger coverage, a lengthening effect on the hand, and striking visual presence. The ideal ratio centers around 2.00, then there’s of course adjustments based on personal preferences at times. the ratios below have consistently proven to deliver the most balanced, elegant, and desirable appearance that sets a lozenge cut apart from every other shape.

	EXCELLENT	VERY GOOD	GOOD
Length To Width Ratio	1.85 – 2.15	1.70 – 2.40	1.50 – 2.60