Gemstone Carat Converter
Convert gemstone weight between carats, points, grams, grains and other jewelry units
Result
1 Carat (ct) = 0.2 Gram (g)
Carats
1 ct
Points
100 pts
Grams
0.2 g
All Conversions
Carat (ct)1
Point (1/100 ct)100
Gram (g)0.2
Milligram (mg)200
Grain (gr)3.0864
Troy Ounce (oz t)0.0064
Pennyweight (dwt)0.1286
Momme (pearl unit)0.0533
Ratti (Indian)1.6461
Tola (Indian)0.0171
Round Diamond Size Chart
| Weight | Diameter (mm) | Description |
|---|---|---|
| 0.25 ct | 4.1 mm | 1/4 carat |
| 0.5 ct | 5.2 mm | 1/2 carat |
| 0.75 ct | 5.9 mm | 3/4 carat |
| 1 ct | 6.5 mm | 1 carat |
| 1.5 ct | 7.4 mm | 1.5 carat |
| 2 ct | 8.2 mm | 2 carat |
| 3 ct | 9.4 mm | 3 carat |
| 4 ct | 10.4 mm | 4 carat |
| 5 ct | 11.1 mm | 5 carat |
*Sizes are approximate for ideal-cut round brilliant diamonds
About Gemstone Weight Units
Carat (ct): The standard unit for gemstones. 1 carat = 200 milligrams = 0.2 grams.
Point: 1/100th of a carat, used for small diamonds. A 50-point diamond is 0.50 carats.
Momme: Traditional Japanese unit for pearls. 1 momme = 3.75 grams.
Note: Gemstone carat is different from gold karat, which measures purity.