Professional French Cut Diamond Size Chart
Detailed Carat to MM / MM to Carat French Cut Diamond Size Chart
The French cut diamond is one of the most beloved vintage cuts, proven by the fact that it is still prized today. Originating in the 16th century and later revived during the Art Deco era, this square or rectangular shape features a high crown and a signature criss-cross pattern of triangular facets that create its uniquely beautiful four-pointed star effect when viewed from above.
With fewer but larger facets than modern cuts, the French cut produces soft, reflective flashes of light rather than intense sparkle, giving it its own unique personality. Its structured geometry makes it a standout choice for anyone seeking something truly unique and full of the charm reminiscent of the old world.
Below you will find professionally compiled carat to millimeter conversion chart along with clear, practical recommendations on depth, table, girdle, culet, and length to width ratios. These will help you confidently choose or advise on the perfect French cut diamond every time.
French Cut Diamond MM Size Chart / CT Conversion Chart
0.25 - 5.00 cts
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| FRENCH CUT DIAMOND CARAT WEIGHT | FRENCH CUT DIAMOND MM SIZE |
|---|---|
| 0.25 | 3.36 - 3.61 mm. |
| 0.3 | 3.58 - 3.83 mm. |
| 0.4 | 3.95 - 4.20 mm. |
| 0.5 | 4.26 - 4.51 mm. |
| 0.6 | 4.54 - 4.79 mm. |
| 0.7 | 4.78 - 5.03 mm. |
| 0.8 | 5.00 - 5.25 mm. |
| 0.9 | 5.21 - 5.46 mm. |
| 1 | 5.40 - 5.65 mm. |
| 1.2 | 5.75 - 6.00 mm. |
| 1.3 | 5.90 - 6.15 mm. |
| 1.4 | 6.06 - 6.31 mm. |
| 1.5 | 6.20 - 6.45 mm. |
| 1.6 | 6.34 - 6.59 mm. |
| 1.7 | 6.47 - 6.72 mm. |
| 1.8 | 6.59 - 6.84 mm. |
| 1.9 | 6.72 - 6.97 mm. |
| 2 | 6.83 - 7.08 mm. |
| 2.2 | 7.06 - 7.31 mm. |
| 2.5 | 7.37 - 7.62 mm. |
| 2.7 | 7.57 - 7.82 mm. |
| 3 | 7.84 - 8.09 mm. |
| 3.5 | 8.26 - 8.51 mm. |
| 4 | 8.64 - 8.89 mm. |
| 4.5 | 8.99 - 9.24 mm. |
| 5 | 9.32 - 9.57 mm. |
Ava Diamonds
French Cut Diamond on Hand
A French cut diamond brings a vintage charm and character when worn on the finger. This square or rectangular shape features a high crown and distinctive criss-cross triangular facets that create a four-pointed star pattern visible from above, giving it a unique optical depth and elegance.
The step-cut style produces large, reflective flashes rather than intense sparkle, resulting in a soft yet captivating brilliance that feels refined and timeless. Its balanced proportions sit comfortably with good coverage, and the cut often appears surprisingly substantial in real life thanks to the way light plays across the larger facets.
The following visual aid demonstrates how a French Cut looks like on Hand, starting from 0.75 carats all the way to 3.00 carats.
What are the Ideal Proportions of a French Cut?
The French cut is a classic vintage style that demands precise proportions to achieve its signature star-like reflection and balanced geometric appearance. Because of its high crown, smaller table, and distinctive criss-cross facet arrangement, ideal measurements help maximize light performance while preserving the refined, structured look that makes this cut so special.
What is the Ideal Diamond Depth and Table for the French Cut?
| EXCELLENT | VERY GOOD | GOOD | |
|---|---|---|---|
Table - % | 48% - 56% | 46% - 59% | 44% – 62% |
Depth - % | 63% - 70% | 60% - 73% | 58% - 76% |
Girdle | Thin to Slightly Thick | Very Thin to Thick | Very Thin to Very Thick |
Culet | None to Small | Small to Medium | Medium to Large |
What is the Ideal French Cut Diamond Length to Width Ratio?
Achieving the right balance of depth and table percentage is essential for the French cut to display its soft reflective brilliance without appearing too dark or overly flat. The following guidelines, developed through extensive gemological experience with vintage cuts, ensure the stone shows off its unique star pattern and impressive face-up size.
| EXCELLENT | VERY GOOD | GOOD | |
|---|---|---|---|
| Length To Width Ratio | 1.00 – 1.05 | 0.98 – 1.10 | 0.95 – 1.15 |