Round Cut Diamonds

Diamond Shape: Round Cut

Round diamonds are as classic as they are timeless and are often the shape people think of when picturing diamonds. Variations of the round shape have been used as long as diamonds have been cut. Their scintillating glimmer keeps them popular, and the round cut is considered to be the gold standard for diamonds in the eyes of diamond connoisseurs, gemologists, and everyday consumers. Interestingly, a round cut loses more of its original diamond carat weight during cutting and processing than any other shape. This, more than the shape's popularity, is what makes round cut diamonds more expensive than other shapes.

A round diamond's brilliance is enhanced by its cut which is determined by the use of scientific calculations performed by expert diamond cutters. These calculations help create a better cut, polish and symmetry, making a round diamond appear even more brilliant. With other diamond shapes, settling for lower grades of color or clarity usually means sacrificing some of the beauty of the stone. Round diamonds, because they are better at reflecting light and dispelling color, usually maintain the same aesthetic appeal, even when they have a lower clarity or color rating.

Round Cut Diamond Guide

Every diamond shape has a length-to-width ratio that determines how a diamond will appear when viewed from above. When selecting a loose round diamond, look for a length-to-width ratio between 1.0 and 1.05.

Diamond Size Chart

Depth % Range for Round Cut Diamonds

Round Diamond | Side View

Ideal

63-59.5

Excellent

63.5-59

Very Good

64-58

Good

65-57.5

Table % Range for Round Cut Diamonds

Round Diamond | Top View

Ideal

59-54

Excellent

60-53

Very Good

61-52

Good

63-52

Length to Width for Round Cut Diamonds (L÷W = Length to Width Ratio)

Round Diamond | Length to Width (1.0)
1.0
Round Diamond | Length to Width (1.05)
1.05

Diamond Carat Size Comparison Chart for Round Cut Diamonds

MM SizeCarat Weight
0.8 mm.0.0025 ct.
1 mm.0.005 ct.
1.1 mm.0.0067 ct.
1.2 mm.0.009 ct.
MM SizeCarat Weight
1.25 mm.0.01 ct.
1.3 mm.0.01 ct.
1.5 mm.0.015 ct.
1.75 mm.0.02 ct.
DIAMOND SEARCH

EDUCATION

LEARN ALL ABOUT DIAMONDS.

START HERE
Diamond Experts

DIAMOND EXPERTS

HAVE QUESTIONS? LET US HELP.

Diamond Experts