Moissanite & Lab Diamond Size Chart (Round Cut)

Carat Weight	Diameter (mm)	Carat Weight	Diameter (mm)
0.5 CT	~5.0 mm	1.5 CT	~7.3 mm
0.75 CT	~5.7 mm	2 CT	~8.0 mm
1 CT	~6.3 mm	3 CT	~9.1 mm
1.25 CT	~6.8 mm	5 CT	~10.7 mm

Fancy Shape Size Reference (1 CT Equivalent)

Shape	Length × Width (mm)	Shape	Length × Width (mm)
Round	~6.3 × 6.3 mm	Cushion	~5.5 × 5.5 mm
Oval	~7.7 × 5.9 mm	Emerald	~7.0 × 5.0 mm
Princess	~5.5 × 5.5 mm	Pear	~8.5 × 5.5 mm

Ruby & Sapphire Size Chart (Round Cut)

Corundum (ruby and sapphire) is denser than diamond, so the same carat weight produces a slightly smaller stone. Use the chart below as a general guide.

Carat Weight	Diameter (mm)	Carat Weight	Diameter (mm)
0.5 CT	~4.7 mm	2 CT	~7.5 mm
1 CT	~6.0 mm	3 CT	~8.5 mm
1.5 CT	~6.9 mm	5 CT	~10.1 mm

Emerald Size Chart (Round Cut)

Emerald (beryl) is less dense than diamond, so the same carat weight produces a slightly larger stone.

Carat Weight	Diameter (mm)	Carat Weight	Diameter (mm)
0.5 CT	~5.3 mm	2 CT	~8.4 mm
1 CT	~6.6 mm	3 CT	~9.6 mm
1.5 CT	~7.6 mm	5 CT	~11.3 mm

Note: All measurements are approximate. Actual dimensions may vary slightly based on cutting style and proportions.