CARAT WEIGHT	LENGTH MM SIZE	SHOULDER WIDTH MM SIZE	END WIDTH MM SIZE	DEPTH MM SIZE
0.25 - 0.35 ct	5.00 - 5.50 mm	3.20 - 3.50 mm	2.00 - 2.20 mm	2.20 - 2.40 mm
0.36 - 0.45 ct	5.50 - 6.00 mm	3.50 - 3.80 mm	2.20 - 2.40 mm	2.40 - 2.60 mm
0.46 - 0.55 ct	6.00 - 6.50 mm	3.80 - 4.10 mm	2.40 - 2.60 mm	2.60 - 2.80 mm
0.56 - 0.75 ct	6.50 - 7.00 mm	4.10 - 4.40 mm	2.60 - 2.80 mm	2.80 - 3.00 mm
0.76 - 0.95 ct	7.00 - 7.50 mm	4.40 - 4.70 mm	2.80 - 3.00 mm	3.00 - 3.20 mm
0.96 - 1.25 ct	7.50 - 8.00 mm	4.70 - 5.00 mm	3.00 - 3.20 mm	3.20 - 3.40 mm
1.26 - 1.50 ct	8.00 - 8.50 mm	5.00 - 5.30 mm	3.20 - 3.40 mm	3.40 - 3.60 mm
1.51 - 1.75 ct	8.50 - 9.00 mm	5.30 - 5.60 mm	3.40 - 3.60 mm	3.60 - 3.80 mm
1.76 - 2.00 ct	9.00 - 9.50 mm	5.60 - 5.90 mm	3.60 - 3.80 mm	3.80 - 4.00 mm
2.01 - 2.25 ct	9.50 - 10.00 mm	5.90 - 6.20 mm	3.80 - 4.00 mm	4.00 - 4.20 mm
2.26 - 2.50 ct	10.00 - 10.50 mm	6.20 - 6.50 mm	4.00 - 4.20 mm	4.20 - 4.40 mm
2.51 - 2.75 ct	10.50 - 11.00 mm	6.50 - 6.80 mm	4.20 - 4.40 mm	4.40 - 4.60 mm
2.76 - 3.00 ct	11.00 - 11.50 mm	6.80 - 7.10 mm	4.40 - 4.60 mm	4.60 - 4.80 mm

Note: Coffin cut diamonds feature an elongated hexagonal shape with tapered ends, similar to an elongated shield cut

Professional Coffin Cut Diamond Size Chart