Radiant Diamond Size Chart

Actual mm dimensions for radiant diamonds at every carat weight.

Round

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Radiant Sizes

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MM Size	Carat Weight
3.5 x 3.5 mm	0.25 ct
3.8 x 3.8 mm	0.33 ct
4.5 x 4.5 mm	0.5 ct
4.8 x 4.8 mm	0.6 ct
5.2 x 5.2 mm	0.75 ct
5.5 x 5.5 mm	0.9 ct
5.7 x 5.7 mm	1 ct
6.1 x 6.1 mm	1.25 ct
6.5 x 6.5 mm	1.5 ct

MM Size	Carat Weight
6.8 x 6.8 mm	1.75 ct
7.2 x 7.2 mm	2 ct
7.6 x 7.6 mm	2.5 ct
8.1 x 8.1 mm	3 ct
8.5 x 8.5 mm	3.5 ct
8.9 x 8.9 mm	4 ct
9.2 x 9.2 mm	4.5 ct
9.5 x 9.5 mm	5 ct

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

About radiant diamond measurements

These are approximate face-up dimensions for well-cut radiant 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.