Shape Guide

Diamond Shape Size and Carat Weight

Tap a shape above to switch the size reference. Each shape opens its own size-to-carat guide for quick comparison.

Round Size Guide

Round MM Size and Carat Weight

Round MM SizeRound Carat Weight
0.8 mm0.0025 ct
1 mm0.005 ct
1.1 mm0.0067 ct
1.2 mm0.009 ct
1.25 mm0.01 ct
1.3 mm0.01 ct
1.5 mm0.015 ct
1.75 mm0.02 ct
1.8 mm0.025 ct
2 mm0.03 ct
2.2 mm0.04 ct
2.5 mm0.06 ct
2.75 mm0.08 ct
3 mm0.10 ct
3.25 mm0.14 ct
3.5 mm0.17 ct
3.75 mm0.21 ct
4 mm0.25 ct
4.25 mm0.28 ct
4.5 mm0.36 ct
4.75 mm0.44 ct
5.0 mm0.50 ct
5.25 mm0.56 ct
5.5 mm0.66 ct
5.75 mm0.75 ct
6 mm0.84 ct
6.25 mm0.93 ct
6.5 mm1.00 ct
6.8 mm1.25 ct
Round MM SizeRound Carat Weight
7 mm1.30 ct
7.3 mm1.50 ct
7.5 mm1.67 ct
7.75 mm1.75 ct
8 mm2.00 ct
8.25 mm2.11 ct
8.5 mm2.43 ct
8.7 mm2.50 ct
9 mm2.75 ct
9.1 mm3.00 ct
9.5 mm3.35 ct
9.75 mm3.61 ct
10 mm3.87 ct
10.25 mm4.16 ct
10.5 mm4.41 ct
10.75 mm4.57 ct
11 mm4.91 ct
11.25 mm5.49 ct
11.5 mm5.85 ct
12 mm6.84 ct
12.25 mm7.26 ct
12.5 mm7.36 ct
12.75 mm7.52 ct
13 mm8.51 ct
13.5 mm9.53 ct
14 mm10.49 ct
15 mm12.89 ct
16 mm16.06 ct

Princess Size Guide

Princess MM Size and Carat Weight

Princess MM SizePrincess Carat Weight
1.5 mm0.015 ct
1.75 mm0.03 ct
2 mm0.06 ct
2.25 mm0.08 ct
2.5 mm0.10 ct
2.75 mm0.13 ct
3 mm0.18 ct
3.25 mm0.26 ct
3.5 mm0.29 ct
3.75 mm0.31 ct
4 mm0.39 ct
4.25 mm0.44 ct
4.5 mm0.50 ct
4.75 mm0.64 ct
5 mm0.75 ct
5.25 mm0.90 ct
5.5 mm1.00 ct
5.75 mm1.11 ct
6 mm1.25 ct
Princess MM SizePrincess Carat Weight
6.5 mm1.50 ct
6.75 mm1.75 ct
7 mm2.00 ct
7.25 mm2.01 ct
7.5 mm2.50 ct
7.75 mm2.74 ct
8 mm3.00 ct
8.25 mm3.24 ct
8.5 mm3.67 ct
8.75 mm4.10 ct
9 mm4.12 ct
9.5 mm5.09 ct
9.75 mm5.36 ct
10 mm5.62 ct
10.25 mm5.76 ct
10.5 mm5.99 ct
11 mm7.44 ct
11.5 mm9.44 ct
12 mm9.52 ct

Asscher Size Guide

Asscher MM Size and Carat Weight

Asscher MM SizeAsscher Carat Weight
4 mm0.39 ct
4.5 mm0.50 ct
5 mm0.75 ct
5.5 mm1.00 ct
6 mm1.25 ct
6.5 mm1.50 ct
7 mm2.00 ct
7.5 mm2.50 ct
8 mm3.00 ct
8.5 mm3.50 ct
9 mm4.12 ct
9.5 mm5.09 ct
10 mm5.62 ct
11 mm7.44 ct
12 mm9.52 ct
13 mm12.66 ct

Radiant Size Guide

Radiant MM Size and Carat Weight

Radiant MM SizeRadiant Carat Weight
5x3 mm0.31 ct
4.5x3.5 mm0.34 ct
6x5 mm0.41 ct
6x4 mm0.50 ct
6.5x4.5 mm0.75 ct
7x5 mm1.00 ct
7.3x5.5 mm1.25 ct
7.5x5.8 mm1.50 ct
8x6 mm2.00 ct
8.5x6.5 mm2.25 ct
9x7 mm2.50 ct
9.5x7.5 mm3.00 ct
10x7 mm3.31 ct
10x8 mm3.50 ct
11x9 mm5.05 ct
12x9 mm6.06 ct
11.5x10 mm6.45 ct
13x9 mm6.54 ct
12x10 mm6.79 ct
14x10 mm8.47 ct
13x11 mm9.33 ct
13.5x11.5 mm10.19 ct
15x11 mm11.48 ct
14x12 mm12.14 ct
16x12 mm14.22 ct
Radiant MM SizeRadiant Carat Weight
5x3 mm0.31 ct
4.5x3.5 mm0.34 ct
6x5 mm0.41 ct
6x4 mm0.50 ct
6.5x4.5 mm0.75 ct
7x5 mm1.00 ct
7.3x5.5 mm1.25 ct
7.5x5.8 mm1.50 ct
8x6 mm2.00 ct
8.5x6.5 mm2.25 ct
9x7 mm2.50 ct
9.5x7.5 mm3.00 ct
10x7 mm3.31 ct
10x8 mm3.50 ct
11x9 mm5.05 ct
12x9 mm6.06 ct
11.5x10 mm6.45 ct
13x9 mm6.54 ct
12x10 mm6.79 ct
14x10 mm8.47 ct
13x11 mm9.33 ct
13.5x11.5 mm10.19 ct
15x11 mm11.48 ct
14x12 mm12.14 ct
16x12 mm14.22 ct

Cushion Size Guide

Cushion MM Size and Carat Weight

Cushion MM SizeCushion Carat Weight
4.2 mm0.40 ct
4.9 mm0.50 ct
5.25 mm0.75 ct
5.5 mm1.00 ct
6 mm1.25 ct
6.5 mm1.50 ct
7 mm2.00 ct
7.5 mm2.50 ct
8 mm3.00 ct
8.5 mm3.50 ct
9 mm4.12 ct
9.5 mm5.09 ct
10 mm5.62 ct
11 mm7.44 ct
12 mm9.52 ct
13 mm12.66 ct
Cushion MM SizeCushion Carat Weight
4.2 mm0.40 ct
4.9 mm0.50 ct
5.25 mm0.75 ct
5.5 mm1.00 ct
6 mm1.25 ct
6.5 mm1.50 ct
7 mm2.00 ct
7.5 mm2.50 ct
8 mm3.00 ct
8.5 mm3.50 ct
9 mm4.12 ct
9.5 mm5.09 ct
10 mm5.62 ct
11 mm7.44 ct
12 mm9.52 ct
13 mm12.66 ct

Emerald Size Guide

Emerald MM Size and Carat Weight

Emerald MM SizeEmerald Carat Weight
3x2 mm0.10 ct
3.5x2 mm0.12 ct
4x2 mm0.15 ct
4x3 mm0.20 ct
5x3 mm0.29 ct
5.5x3.5 mm0.46 ct
6x4 mm0.50 ct
6.5x4.5 mm0.75 ct
6.7x4.5 mm0.88 ct
7x5 mm1.00 ct
7.3x5.3 mm1.25 ct
7.5x5.5 mm1.50 ct
8x6 mm1.75 ct
8.5x6.5 mm2.00 ct
9x7 mm2.50 ct
10x7.5 mm3.00 ct
9.5x7.5 mm3.21 ct
10x8 mm3.79 ct
11x9 mm5.21 ct
12x10 mm6.00 ct
14x8 mm6.25 ct
13x9 mm6.38 ct
14x10 mm8.48 ct
13x11 mm9.13 ct
14x12 mm11.26 ct
16x12 mm14.22 ct

Marquise Size Guide

Marquise MM Size and Carat Weight

Marquise MM SizeMarquise Carat Weight
3x1.5 mm0.025 ct
3.5x1.75 mm0.065 ct
3.5x2 mm0.07 ct
4x2 mm0.10 ct
3.75x1.75 mm0.11 ct
4.25x2.25 mm0.12 ct
5x2.5 mm0.14 ct
5.5x2.75 mm0.16 ct
5.5x3 mm0.18 ct
5x3 mm0.20 ct
6.5x3 mm0.23 ct
6x3 mm0.25 ct
7x3 mm0.30 ct
7.5x3.5 mm0.33 ct
7x4 mm0.34 ct
8x4 mm0.50 ct
8.75x4.25 mm0.70 ct
9x4.5 mm0.75 ct
Marquise MM SizeMarquise Carat Weight
9.5x4.7 mm0.85 ct
10x5 mm1.00 ct
11x5.5 mm1.25 ct
11.5x6 mm1.33 ct
12x6 mm1.50 ct
13x6.5 mm2.00 ct
14x7 mm2.50 ct
15x7 mm3.00 ct
14x8 mm3.00 ct
15x7.5 mm3.25 ct
15x8 mm3.44 ct
16x8 mm3.86 ct
16.5x8.25 mm4.00 ct
17x8.5 mm4.88 ct
17.5x10 mm5.50 ct
20x8 mm7.08 ct
20x10 mm7.94 ct
20x11 mm9.50 ct

Oval Size Guide

Oval MM Size and Carat Weight

Oval MM SizeOval Carat Weight
3.6x2.7 mm0.10 ct
4x3 mm0.15 ct
4.5x3.5 mm0.20 ct
5x3.5 mm0.25 ct
5.5x3.5 mm0.33 ct
5x4 mm0.35 ct
6x4 mm0.50 ct
6x5 mm0.61 ct
6.5x4.5 mm0.65 ct
7x5 mm0.75 ct
7.7x5.7 mm1.00 ct
8x6 mm1.25 ct
9x6 mm1.41 ct
8.5x6.5 mm1.50 ct
9x7 mm2.00 ct
10x8 mm2.50 ct
10.5x8.5 mm2.88 ct
12x8 mm3.00 ct
11x9 mm3.85 ct
12x10 mm5.05 ct
14x10 mm5.81 ct
13x11 mm6.05 ct
14x12 mm8.21 ct
15x12 mm8.76 ct
16x12 mm9.32 ct
16x14 mm11.88 ct
18x13 mm12.86 ct
20x15 mm14.96 ct

Pear Size Guide

Pear MM Size and Carat Weight

Pear MM SizePear Carat Weight
3x2 mm0.13 ct
4x2.5 mm0.18 ct
4x3 mm0.21 ct
5x3 mm0.25 ct
5x4 mm0.35 ct
6x4 mm0.50 ct
6.5x4.5 mm0.60 ct
7x5 mm0.75 ct
7.5x5.5 mm0.85 ct
7.7x5.7 mm1.00 ct
8x6 mm1.25 ct
8.5x6.5 mm1.50 ct
10x6 mm1.71 ct
8.7x6.7 mm1.80 ct
9x7 mm2.00 ct
10x8 mm2.50 ct
11x7.50 mm2.61 ct
11x8 mm2.70 ct
12x8 mm3.00 ct
Pear MM SizePear Carat Weight
12x7 mm3.12 ct
13x8 mm3.40 ct
12x9 mm3.44 ct
14x8 mm4.00 ct
13x9 mm4.11 ct
14x9 mm4.25 ct
15x9 mm5.06 ct
14x10 mm5.41 ct
13x11 mm5.65 ct
15x10 mm5.75 ct
16x9 mm5.86 ct
16x10 mm6.27 ct
17x10 mm6.46 ct
15x11 mm7.36 ct
18x11 mm8.14 ct
16x12 mm8.99 ct
18x12 mm9.35 ct
18x13 mm10.21 ct

Heart Size Guide

Heart MM Size and Carat Weight

Heart MM SizeHeart Carat Weight
3.5 mm0.18 ct
4 mm0.25 ct
4.25 mm0.28 ct
4.5 mm0.34 ct
4.75 mm0.38 ct
5 mm0.50 ct
5.5 mm0.61 ct
6 mm0.75 ct
6.25 mm0.83 ct
6.5 mm1.00 ct
7 mm1.25 ct
7.5 mm1.50 ct
8 mm2.00 ct
8.5 mm2.50 ct
9 mm3.00 ct
10 mm3.50 ct
11 mm4.41 ct
12 mm5.66 ct
13 mm7.88 ct
14 mm9.38 ct
15 mm10.79 ct
16 mm13.27 ct
18 mm15.33 ct