Radiant moissanite size chart: mm to carat
By HeyGema™ · Updated
In short
A radiant moissanite labeled 1 carat measures about 6.5 x 5.0 mm, the size of a 1 carat radiant diamond. It weighs about 0.91 carat on a scale, because moissanite is lighter than diamond.
Carat to mm calculator
About 6.7 x 5.2 mm
An estimate for a well-cut stone. A deep or shallow cut faces up smaller or bigger.
Radiant moissanite: size, DEW and true weight
Sizes are length x width in mm of a well-cut radiant at a ratio of 1.30:1. DEW is diamond equivalent weight, the label most stores use. True weight is what the stone weighs.
- 0.5 ct
- Length x width: 5.2 x 4.0 mm
- True weight: 0.46 ct
- Weight in grams: 0.092 g
- 0.75 ct
- Length x width: 5.9 x 4.5 mm
- True weight: 0.69 ct
- Weight in grams: 0.14 g
- 1 ct
- Length x width: 6.5 x 5.0 mm
- True weight: 0.91 ct
- Weight in grams: 0.18 g
- 1.5 ct
- Length x width: 7.4 x 5.7 mm
- True weight: 1.37 ct
- Weight in grams: 0.27 g
- 2 ct
- Length x width: 8.2 x 6.3 mm
- True weight: 1.83 ct
- Weight in grams: 0.37 g
- 3 ct
- Length x width: 9.4 x 7.2 mm
- True weight: 2.74 ct
- Weight in grams: 0.55 g
- 4 ct
- Length x width: 10.3 x 7.9 mm
- True weight: 3.66 ct
- Weight in grams: 0.73 g
- 5 ct
- Length x width: 11.1 x 8.5 mm
- True weight: 4.57 ct
- Weight in grams: 0.91 g
Radiant moissanite by length-to-width ratio
A 1 carat DEW stone at each ratio. The size changes with the ratio, so check the length and the width in the listing.
- 1.00:1
- Length x width: 5.7 x 5.7 mm
- 1.15:1
- Length x width: 6.1 x 5.3 mm
- 1.30:1
- Length x width: 6.5 x 5.0 mm
- 1.40:1
- Length x width: 6.7 x 4.8 mm
Questions
A 1 carat DEW radiant moissanite is about 6.5 x 5.0 mm.
A 2 carat DEW radiant moissanite is about 8.2 x 6.3 mm.
No. DEW is the weight of a diamond the same size. A moissanite weighs about 9% less than that.