Trilliant Diamond Size Chart

Actual mm dimensions for trilliant diamonds at every carat weight.

Round

How big is act Trilliant?

Trilliant Sizes

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MM Size	Carat Weight
2.5 x 2.5 mm	0.05 ct
3 x 3 mm	0.08 ct
3.5 x 3.5 mm	0.1 ct
4 x 4 mm	0.15 ct
4.5 x 4.5 mm	0.2 ct
5 x 5 mm	0.25 ct
5.5 x 5.5 mm	0.33 ct
5.8 x 5.8 mm	0.4 ct
6 x 6 mm	0.5 ct
6.3 x 6.3 mm	0.6 ct

MM Size	Carat Weight
6.5 x 6.5 mm	0.75 ct
7 x 7 mm	1 ct
7.5 x 7.5 mm	1.25 ct
8 x 8 mm	1.5 ct
8.5 x 8.5 mm	2 ct
9.2 x 9.2 mm	2.5 ct
9.5 x 9.5 mm	3 ct
10.5 x 10.5 mm	4 ct
11.5 x 11.5 mm	5 ct

Approximate dimensions for well-cut stones. Always verify against the grading report.

About trilliant diamond measurements

These are approximate face-up dimensions for well-cut trilliant diamonds with standard proportions. Actual size depends on cut depth, girdle thickness, and length-to-width ratio choices.

Always check the specific mm measurements on the grading report before buying. A stone that's technically 1 carat but cut deep will look noticeably smaller than one cut to proper proportions.