Diamond Size Chart · Fastemy

Diamond Size Chart

Carat weight

Selected stone

1.00 ct round, 6.4 mm

Face-up size: 6.4 mm
Face-up area vs 1 ct round: 100%
Weight: 0.20 g

Drawn in CSS millimetres — close to true size on most screens, not exact. Figures assume typical proportions; a lab report lists a stone’s real measurements.

Diamond carat weight to face-up millimetres, by shape
Carat	Round	Oval	Princess	Cushion	Emerald	Radiant	Asscher	Pear	Marquise	Heart
0.25 ct	4.1 mm	4.9 × 3.6 mm	3.5 × 3.5 mm	3.5 × 3.5 mm	4.2 × 3.0 mm	3.8 × 3.1 mm	3.5 × 3.5 mm	5.5 × 3.5 mm	6.6 × 3.3 mm	4.1 × 4.1 mm
0.50 ct	5.1 mm	6.1 × 4.5 mm	4.4 × 4.4 mm	4.4 × 4.4 mm	5.2 × 3.8 mm	4.8 × 4.0 mm	4.4 × 4.4 mm	6.9 × 4.4 mm	8.3 × 4.2 mm	5.2 × 5.2 mm
0.75 ct	5.8 mm	7.0 × 5.2 mm	5.0 × 5.0 mm	5.0 × 5.0 mm	6.0 × 4.4 mm	5.5 × 4.5 mm	5.0 × 5.0 mm	7.9 × 5.0 mm	9.5 × 4.8 mm	5.9 × 5.9 mm
1.00 ct	6.4 mm	7.7 × 5.7 mm	5.5 × 5.5 mm	5.5 × 5.5 mm	6.6 × 4.8 mm	6.0 × 5.0 mm	5.5 × 5.5 mm	8.7 × 5.5 mm	10.5 × 5.3 mm	6.5 × 6.5 mm
1.25 ct	6.9 mm	8.3 × 6.1 mm	5.9 × 5.9 mm	5.9 × 5.9 mm	7.1 × 5.2 mm	6.5 × 5.4 mm	5.9 × 5.9 mm	9.4 × 5.9 mm	11.3 × 5.7 mm	7.0 × 7.0 mm
1.50 ct	7.4 mm	8.8 × 6.5 mm	6.3 × 6.3 mm	6.3 × 6.3 mm	7.6 × 5.5 mm	6.9 × 5.7 mm	6.3 × 6.3 mm	10.0 × 6.3 mm	12.0 × 6.1 mm	7.4 × 7.4 mm
2.00 ct	8.1 mm	9.7 × 7.2 mm	6.9 × 6.9 mm	6.9 × 6.9 mm	8.3 × 6.0 mm	7.6 × 6.3 mm	6.9 × 6.9 mm	11.0 × 6.9 mm	13.2 × 6.7 mm	8.2 × 8.2 mm
2.50 ct	8.7 mm	10.5 × 7.7 mm	7.5 × 7.5 mm	7.5 × 7.5 mm	9.0 × 6.5 mm	8.1 × 6.8 mm	7.5 × 7.5 mm	11.8 × 7.5 mm	14.3 × 7.2 mm	8.8 × 8.8 mm
3.00 ct	9.3 mm	11.1 × 8.2 mm	7.9 × 7.9 mm	7.9 × 7.9 mm	9.5 × 6.9 mm	8.7 × 7.2 mm	7.9 × 7.9 mm	12.5 × 7.9 mm	15.1 × 7.6 mm	9.4 × 9.4 mm
4.00 ct	10.2 mm	12.2 × 9.0 mm	8.7 × 8.7 mm	8.7 × 8.7 mm	10.5 × 7.6 mm	9.5 × 7.9 mm	8.7 × 8.7 mm	13.8 × 8.7 mm	16.7 × 8.4 mm	10.3 × 10.3 mm
5.00 ct	11.0 mm	13.2 × 9.7 mm	9.4 × 9.4 mm	9.4 × 9.4 mm	11.3 × 8.2 mm	10.3 × 8.5 mm	9.4 × 9.4 mm	14.9 × 9.4 mm	18.0 × 9.1 mm	11.1 × 11.1 mm