MM To Carat Conversion Table here gives you the idea in what size the stone may weigh. The word 'carat' comes from the 'carob' seed, which was originally used to measure the weight of diamonds. A carat (ct) is equal to 0.2 grams. Cart is unrelated to similar sounding karat which is used to measure the purity of gold. Given here is the MM To Carat Weight Chart, which provides the weight of the gemstones in carat (ct) against different sizes of the stones.
| Rounds | Squares | Ovals | Emerald | Pear | Marquis | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Size (mm) | Weight (carat) | Size (mm) | Weight (carat) | Size (mm) | Weight (carat) | Size (mm) | Weight (carat) | Size (mm) | Weight (carat) | Size (mm) | Weight (carat) | ||||||
| 1.6 | .02 | 5 | .75 | 5x3 | .25 | 6x4 | .5 | 6x5 | .7 | 4x2 | .10 | ||||||
| 2 | .03 | 6 | 1.3 | 6x4 | .5 | 7x5 | 1.0 | 7x5 | .75 | 5x2.5 | .25 | ||||||
| 2.5 | .06 | 7 | 2.05 | 7x5 | 1.0 | 8x6 | 1.5 | 8x5 | 1.0 | 6x3 | .30 | ||||||
| 3 | .10 | 8 | 2.9 | 8x6 | 1.5 | 9x7 | 2.5 | 9x6 | 1.5 | 8x4 | .75 | ||||||
| 3.5 | .16 | 9 | 4.4 | 9x7 | 2.5 | 10x8 | 3.0 | 10x7 | 2.0 | 10x5 | 1.0 | ||||||
| 4 | .25 | 10 | 6.0 | 10x8 | 3.0 | 11x9 | 4.0 | 11x7 | 2.25 | 12x6 | 2.0 | ||||||
| 4.5 | .33 | 11 | 8.0 | 11x9 | 4.0 | 12x10 | 5.0 | 12x8 | 3.0 | 14x7 | 3.0 | ||||||
| 5 | .50 | 12 | 10.35 | 12x10 | 5.0 | 14x10 | 6.0 | 13 x9 | 3.5 | 16x8 | 4.0 | ||||||
| 5.5 | .65 | 13 | 13.2 | 14x10 | 6.0 | 14x12 | 8.0 | 15x10 | 5.5 | 18x9 | 6.0 | ||||||
| 6 | .75 | 14 | 16.5 | 14x12 | 8.0 | 16x12 | 10.5 | 16x12 | 8.6 | 20x10 | 8.5 | ||||||
| 6.5 | 1.0 | 15 | 20.25 | 16x12 | 10.5 | 18x13 | 14.2 | 18x13 | 12 | ||||||||
| 7 | 1.25 | 16 | 24.6 | 18x13 | 14.2 | 20x15 | 20.3 | 20x15 | 17.3 | ||||||||
| 8 | 2.0 | 20x15 | 20.3 | 25x18 | 52.2 | 22x15 | 18.7 | ||||||||||
| 9 | 2.75 | 22x15 | 23.5 | 25x18 | 30.6 | ||||||||||||
| 10 | 3.5 | 23x17 | 32.2 | 30x22 | 54.5 | ||||||||||||
| 11 | 4.6 | 25x18 | 43.0 | ||||||||||||||
| 12 | 6.0 | 27x20 | 58.5 | ||||||||||||||
| 13 | 7.75 | 30x22 | 79.6 | ||||||||||||||
| 14 | 9.65 | ||||||||||||||||
| 15 | 11.85 | ||||||||||||||||
| 16 | 14.35 | ||||||||||||||||
| 17 | 17.25 | ||||||||||||||||
| 18 | 20.5 | ||||||||||||||||
| 19 | 24.0 | ||||||||||||||||
| 20 | 28.0 | ||||||||||||||||
| 21 | 34.8 | ||||||||||||||||
| 22 | 41.8 | ||||||||||||||||
| 23 | 49.8 | ||||||||||||||||
| 24 | 57.9 | ||||||||||||||||
| 25 | 68.7 | ||||||||||||||||
Millimeter(MM) to carat weight against different sizes of the stones ranges from 1.6 mm to 25 mm and for different shapes such as round, square, oval, emerald, pear, marquis. Carat is used for measuring gemstones and pearls. Gemstones with deep cut or very shallow cut will vary for these estimated carat weights.
