Old Mine Cut Diamond Size Chart

Actual mm dimensions for old mine cut diamonds at every carat weight.

Round

How big is act Old Mine Cut?

Old Mine Cut Sizes

Shape guide →

MM Size	Carat Weight
4 x 4 mm	0.25 ct
4.3 x 4.3 mm	0.33 ct
5 x 5 mm	0.5 ct
5.3 x 5.3 mm	0.6 ct
5.6 x 5.6 mm	0.75 ct
6 x 6 mm	0.9 ct
6.2 x 6.2 mm	1 ct
6.5 x 6.5 mm	1.25 ct

MM Size	Carat Weight
7 x 7 mm	1.5 ct
7.3 x 7.3 mm	1.75 ct
7.5 x 7.5 mm	2 ct
8 x 8 mm	2.5 ct
8.5 x 8.5 mm	3 ct
9.5 x 9.5 mm	4 ct
10.5 x 10.5 mm	5 ct

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

About old mine cut diamond measurements

These are approximate face-up dimensions for well-cut old mine cut 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.