Round moissanite size chart: mm to carat
By HeyGema™ · Updated
In short
A round moissanite labeled 1 carat measures about 6.5 mm, the size of a 1 carat round diamond. It weighs about 0.91 carat on a scale, because moissanite is lighter than diamond.
Carat to mm calculator
About 6.6 x 6.6 mm
An estimate for a well-cut stone. A deep or shallow cut faces up smaller or bigger.
Round moissanite: size, DEW and true weight
Sizes are length x width in mm of a well-cut round at a ratio of 1.00:1. DEW is diamond equivalent weight, the label most stores use. True weight is what the stone weighs.
- 0.5 ct
- Length x width: 5.1 mm
- True weight: 0.46 ct
- Weight in grams: 0.092 g
- 0.75 ct
- Length x width: 5.9 mm
- True weight: 0.69 ct
- Weight in grams: 0.14 g
- 1 ct
- Length x width: 6.5 mm
- True weight: 0.91 ct
- Weight in grams: 0.18 g
- 1.5 ct
- Length x width: 7.4 mm
- True weight: 1.37 ct
- Weight in grams: 0.27 g
- 2 ct
- Length x width: 8.1 mm
- True weight: 1.83 ct
- Weight in grams: 0.37 g
- 3 ct
- Length x width: 9.3 mm
- True weight: 2.74 ct
- Weight in grams: 0.55 g
- 4 ct
- Length x width: 10.2 mm
- True weight: 3.66 ct
- Weight in grams: 0.73 g
- 5 ct
- Length x width: 11.0 mm
- True weight: 4.57 ct
- Weight in grams: 0.91 g
Questions
A 1 carat DEW round moissanite is about 6.5 mm.
A 2 carat DEW round moissanite is about 8.1 mm.
No. DEW is the weight of a diamond the same size. A moissanite weighs about 9% less than that.