Custom Jewelry 

MM to Carat Weight Conversion Charts

These conversion charts give estimated values. ct. weight will vary greatly by the depth of the stone.
You can also download and print out our pdf of mm to carat weight conversions.

       
   
Round       Princess    
European, Mine, Portuguese, Lonestar, Sunburst   Quadrillion, Cushion, Asscher, Flanders
Size (mm) CZ ct wt Diamond ct wt   Size (mm) CZ ct wt Diamond ct wt
1.25 0.013 0.010   3.00 0.30 0.18
1.50 0.023 0.015   3.50 0.50 0.29
1.75 0.037 0.020   4.00 0.66 0.39
2.00 0.06 0.03   4.50 0.95 0.56
2.25 0.08 0.04   5.00 1.21 0.71
2.50 0.10 0.05   5.50 1.68 0.99
2.75 0.15 0.08   6.00 2.10 1.24
3.00 0.18 0.11   6.50 2.71 1.59
3.50 0.29 0.17   7.00 3.33 1.96
4.00 0.43 0.25   7.50 4.08 2.40
4.50 0.61 0.36   8.00 5.12 3.01
5.00 0.79 0.46   8.50 6.24 3.67
5.50 1.13 0.66   9.00 7.01 4.12
6.00 1.43 0.84   9.50 8.65 5.09
6.50 1.75 1.03   10.00 9.56 5.62
7.00 2.17 1.28   11.00 12.64 7.44
7.50 2.84 1.67   12.00 16.18 9.52
8.00 3.46 2.04   13.00 21.86 12.86
8.50 4.13 2.43   14.00 25.75 15.15
9.00 4.68 2.75   16.00 40.94 24.08
9.50 5.69 3.35   18.00 55.14 32.44
10.00 6.58 3.87   20.00 72.52 42.66
10.50 7.50 4.41   22.00 99.73 58.66
11.00 8.35 4.91  
11.50 9.94 5.85  
12.00 11.62 6.84  
12.50 12.52 7.36  
13.00 14.47 8.51  
13.50 16.20 9.53  
14.00 17.84 10.49  
15.00 21.92 12.89  
16.00 27.25 16.03  
17.00 33.55 19.74  
18.00 38.60 22.71  
19.00 41.78 24.58  
20.00 50.22 29.54  
22.00 67.43 39.66  
25.00 99.18 58.34  
30.00 181.77 106.92  
40.00 374.15 220.09  
   
   
Emerald       Oval    
             
Size (mm) CZ ct wt Diamond ct wt   Size (mm) CZ ct wt Diamond ct wt
5 x 3 0.50 0.29   5x3 0.35 0.21
6 x 4 1.13 0.66   5x4 0.55 0.32
6.5 x 4.5 1.49 0.88   6x4 0.73 0.43
7 x 5 1.81 1.06   6x5 1.04 0.61
8 x 6 2.95 1.74   7x5 1.30 0.76
8.5 x 6.5 3.69 2.17   7.5x5.5 1.67 0.98
9 x 7 4.46 2.62   8x6 2.06 1.21
9.5 x 7.5 5.46 3.21   9x6 2.40 1.41
10 x 8 6.44 3.79   9x7 3.16 1.86
12 x 8 8.13 4.78   10x8 4.31 2.54
11 x 9 8.85 5.21   10.5x8.5 4.90 2.88
13 x 9 10.84 6.38   12x8 5.09 2.99
12 x 10 11.82 6.95   11x9 6.40 3.85
14 x 10 14.42 8.48   12x10 8.59 5.05
13 x 11 15.52 9.13   14x10 9.87 5.81
14 x 12 19.15 11.26   13x11 10.28 6.05
15 x 11 19.51 11.48   14x12 13.96 8.21
16 x 12 24.18 14.22   15x12 14.89 8.76
18 x 13 32.86 19.33   16x12 15.84 9.32
20 x 15 44.03 25.90   18x13 21.86 12.86
    20x15 32.17 18.92
    22x16 40.84 24.02
Heart      
       
Size (mm) CZ ct wt Diamond ct wt   Marquise    
4.00 0.40 0.24        
4.50 0.57 0.34   Size (mm) CZ ct wt Diamond ct wt
5.00 0.75 0.44   6x3 0.41 0.24
5.50 1.03 0.61   6.5x3.5 0.53 0.31
6.00 1.25 0.74   7x3.5 0.60 0.35
6.25 1.41 0.83   8x3.5 0.69 0.41
6.50 1.58 0.93   8x4 0.80 0.47
7.00 1.92 1.13   9x4.5 1.20 0.71
7.50 2.71 1.59   10x5 1.62 0.95
8.00 2.90 1.71   11x5.5 2.12 1.25
9.00 4.10 2.41   12x6 2.75 1.62
9.50 4.93 2.90   13x6.5 3.60 2.11
10.00 5.38 3.16   14x7 4.22 2.48
11.00 7.50 4.41   15x7.5 5.25 3.09
12.00 9.63 5.66   16x8 6.57 3.86
13.00 13.40 7.88   17x8.5 8.30 4.88
14.00 15.95 9.38   18x9 9.61 5.65
15.00 18.34 10.79   20x10 13.49 7.94
16.00 22.56 13.27   22x11 16.28 9.58
18.00 35.50 20.88   30x15 36.50 21.00
20.00 42.01 24.71  
   
   
   
Pear       Trillion    
             
Size (mm) CZ ct wt Diamond ct wt   Size (mm) CZ ct wt Diamond ct wt
5x4 0.60 0.35   3.50 0.28 0.16
6x4 0.67 0.39   4.00 0.39 0.23
6.5x4.5 0.97 0.57   4.50 0.53 0.31
7x5 1.21 0.71   5.00 0.72 0.42
8x5 1.38 0.81   5.50 0.93 0.55
8.5x5.5 1.83 1.08   6.00 1.19 0.70
9x6 2.26 1.33   6.50 1.55 0.91
9x7 2.98 1.75   7.00 1.87 1.10
10x7 3.06 1.80   7.50 2.06 1.21
10x8 4.19 2.46   8.00 2.97 1.75
11x7.5 4.44 2.61   8.500 3.00 1.76
11x8 5.10 3.00   9.00 3.99 2.35
12x8 5.06 2.98   10.00 5.30 3.12
12x9 5.85 3.44   11.00 6.22 3.66
13x8 5.04 2.98   12.00 8.33 4.90
14x8 5.90 3.47   13.00 10.91 6.42
13x9 6.99 4.11  
14x9 7.01 4.12  
15x9 8.60 5.06  
14x10 9.20 5.41  
13x11 9.61 5.65  
15x10 9.78 5.75  
16x10 10.66 6.27  
17x10 10.99 6.46  
15x11 12.52 7.36  
17x11 13.86 8.05  
18x11 13.84 8.14  
16x12 15.29 8.99  
18x12 15.90 9.35  
18x13 19.83 11.66  
19x12 17.00 10.00  
19x13 20.79 12.23  
20x14 24.92 14.66  
23x13 25.89 15.23  
22x14 26.30 15.47  
20x15 28.65 16.85  
23x14 26.00 25.29  
25x15 30.02 17.66  
25x20 64.00 37.65  

 

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