Diamond Size Chart: MM to Carat Conversion Guide

Diamond Size Chart: MM to Carat Conversion Guide

Asscher Baguette Cushion Emerald Heart Marquise Oval Pear Princess Radiant Round Brilliant Tapered Baguette Trillion Trilliant

Round Brilliant Diamond

Size to Carat Weight Conversion Chart (0.8mm – 10mm)

Size (mm)	Carat Weight (ct)
0.8mm	0.003ct
0.9mm	0.004ct
1.0mm	0.005ct
1.1mm	0.006ct
1.2mm	0.008ct
1.3mm	0.010ct
1.4mm	0.012ct
1.5mm	0.015ct
1.6mm	0.018ct
1.7mm	0.021ct
1.8mm	0.025ct
1.9mm	0.028ct
2.0mm	0.030ct
2.1mm	0.035ct
2.2mm	0.040ct
2.3mm	0.045ct
2.4mm	0.050ct
2.5mm	0.060ct
2.6mm	0.065ct
2.7mm	0.070ct
2.8mm	0.080ct
2.9mm	0.090ct
3.0mm	0.100ct
3.1mm	0.110ct
3.2mm	0.120ct
3.3mm	0.140ct
3.4mm	0.150ct
3.5mm	0.170ct
3.6mm	0.190ct
3.7mm	0.210ct
3.8mm	0.230ct
3.9mm	0.240ct
4.0mm	0.250ct
4.1mm	0.270ct
4.2mm	0.300ct
4.3mm	0.320ct
4.4mm	0.340ct
4.5mm	0.360ct
4.6mm	0.400ct
4.7mm	0.420ct
4.8mm	0.450ct
4.9mm	0.480ct
5.0mm	0.500ct
5.1mm	0.520ct
5.2mm	0.550ct
5.3mm	0.580ct
5.4mm	0.600ct
5.5mm	0.660ct
5.6mm	0.700ct
5.7mm	0.740ct
5.8mm	0.780ct
5.9mm	0.820ct
6.0mm	0.840ct
6.1mm	0.880ct
6.2mm	0.920ct
6.3mm	0.980ct
6.4mm	1.000ct
7.0mm	1.300ct
7.3mm	1.500ct
7.5mm	1.670ct
8.0mm	2.000ct
8.5mm	2.500ct
9.0mm	2.750ct
9.5mm	3.350ct
10.0mm	3.900ct

Princess Cut Diamond

Size to Carat Weight Conversion Chart (1.1mm - 5.5mm)

Size (mm)	Carat Weight (ct)
1.1mm	0.01ct
1.2mm	0.013ct
1.3mm	0.015ct
1.4mm	0.02ct
1.5mm	0.024ct
1.6mm	0.029ct
1.7mm	0.034ct
1.8mm	0.036ct
1.9mm	0.046ct
2mm	0.05ct
2.1mm	0.06ct
2.2mm	0.066ct
2.3mm	0.08ct
2.4mm	0.09ct
2.5mm	0.10ct
2.6mm	0.12ct
2.7mm	0.13ct
2.8mm	0.14ct
2.9mm	0.15ct
3mm	0.16ct
3.1mm	0.20ct
3.2mm	0.20ct
3.3mm	0.23ct
3.4mm	0.25ct
3.5mm	0.28ct
3.6mm	0.32ct
3.7mm	0.33ct
3.8mm	0.35ct
4mm	0.30ct
4.1mm	0.45ct
4.2mm	0.49ct
4.3mm	0.50ct
4.6mm	0.64ct
5mm	0.77ct
5.2mm	0.87ct
5.3mm	0.90ct
5.5mm	1.00ct

Oval Cut Diamond

Size to Carat Weight Conversion Chart

Size (length × width mm)	Carat Weight (ct)
2.5 × 1.8mm	0.04–0.06ct
3.0 × 2.0mm	0.07–0.09ct
3.2 × 2.2mm	0.09–0.11ct
3.4 × 2.3mm	0.11–0.13ct
3.5 × 2.4mm	0.13–0.15ct
3.6 × 2.5mm	0.15ct
3.8 × 2.6mm	0.17–0.19ct
4.0 × 2.7mm	0.20–0.22ct
4.2 × 2.9mm	0.23–0.25ct
4.4 × 3.0mm	0.27–0.30ct
4.5 × 3.1mm	0.30–0.35ct
4.7 × 3.2mm	0.35–0.40ct
4.8 × 3.3mm	0.40–0.45ct
5.0 × 3.0mm	0.35–0.40ct
5.0 × 3.2mm	0.40–0.45ct
5.0 × 3.5mm	0.45–0.50ct
5.2 × 3.4mm	0.45–0.50ct
5.3 × 3.5mm	0.50–0.55ct
5.5 × 3.5mm	0.55–0.60ct
5.5 × 3.7mm	0.60–0.65ct
5.7 × 3.8mm	0.65–0.70ct
6.0 × 4.0mm	0.70–0.80ct
6.0 × 4.2mm	0.80–0.85ct
6.2 × 4.3mm	0.85–0.90ct
6.5 × 4.5mm	0.90–1.00ct

Pear Cut Diamond

Size to Carat Weight Conversion Chart

Size (length × width mm)	Carat Weight (ct)
3.0 × 2.0mm	0.05–0.07ct
3.5 × 2.2mm	0.08–0.10ct
4.0 × 2.5mm	0.13–0.18ct
4.0 × 3.0mm	0.18–0.21ct
4.5 × 2.8mm	0.20–0.23ct
5.0 × 3.0mm	0.25–0.30ct
5.0 × 3.2mm	0.28–0.33ct
5.0 × 3.5mm	0.30–0.35ct
5.2 × 3.3mm	0.32–0.38ct
5.5 × 3.5mm	0.35–0.40ct
5.5 × 3.7mm	0.40–0.45ct
5.7 × 3.8mm	0.45–0.50ct
6.0 × 4.0mm	0.50ct
6.0 × 4.2mm	0.55–0.60ct
6.2 × 4.3mm	0.60–0.65ct
6.5 × 4.5mm	0.65–0.75ct
7.0 × 5.0mm	0.75ct
7.0 × 5.2mm	0.80–0.85ct
7.5 × 5.5mm	0.85–0.90ct
7.7 × 5.7mm	1.00ct
8.0 × 6.0mm	1.10–1.25ct

Marquise Cut Diamond

Size to Carat Weight Conversion Chart

Size (length × width mm)	Carat Weight (ct)
3.5 × 1.8mm	0.04–0.06ct
4.0 × 2.0mm	0.07–0.09ct
4.5 × 2.2mm	0.10–0.12ct
5.0 × 2.5mm	0.13–0.16ct
5.0 × 2.8mm	0.15–0.18ct
5.5 × 2.5mm	0.16–0.19ct
5.5 × 2.8mm	0.18–0.22ct
6.0 × 3.0mm	0.20–0.25ct
6.0 × 3.2mm	0.23–0.28ct
6.5 × 3.0mm	0.25ct
6.5 × 3.3mm	0.28–0.32ct
7.0 × 3.5mm	0.30–0.35ct
7.0 × 3.8mm	0.35–0.40ct
7.5 × 3.5mm	0.33–0.38ct
7.5 × 4.0mm	0.40–0.45ct
8.0 × 4.0mm	0.45–0.50ct
8.0 × 4.2mm	0.50–0.55ct
8.5 × 4.3mm	0.55–0.65ct
9.0 × 4.5mm	0.70–0.80ct
9.5 × 4.8mm	0.85–0.95ct
10.0 × 5.0mm	1.00ct

Radiant Cut Diamond

Size to Carat Weight Conversion Chart

Size (length × width mm)	Carat Weight (ct)
4.0 × 3.0mm	0.25–0.30ct
4.5 × 3.5mm	0.34ct
5.0 × 3.0mm	0.31ct
5.0 × 4.0mm	0.40–0.45ct
5.5 × 4.0mm	0.45–0.50ct
6.0 × 3.0mm	0.41ct
6.0 × 4.0mm	0.50ct
6.0 × 4.5mm	0.55–0.60ct
6.5 × 4.5mm	0.75ct
6.5 × 5.0mm	0.80–0.85ct
7.0 × 5.0mm	1.00ct
7.0 × 5.5mm	1.10–1.15ct
7.3 × 5.5mm	1.25ct
7.5 × 5.8mm	1.50ct
8.0 × 6.0mm	2.00ct
8.5 × 6.5mm	2.25ct
9.0 × 7.0mm	2.50ct

Emerald Cut Diamond

Size to Carat Weight Conversion Chart

Size (length × width mm)	Carat Weight (ct)
3.0 × 2.0mm	0.10ct
4.0 × 3.0mm	0.20–0.25ct
5.0 × 3.0mm	0.25–0.30ct
5.0 × 3.5mm	0.29–0.35ct
5.5 × 3.5mm	0.40–0.46ct
6.0 × 4.0mm	0.50ct
6.0 × 4.5mm	0.55–0.60ct
6.5 × 4.5mm	0.75ct
6.5 × 5.0mm	0.80–0.88ct
7.0 × 5.0mm	1.00ct
7.0 × 5.3mm	1.10–1.25ct
7.5 × 5.5mm	1.50ct
8.0 × 6.0mm	1.75–2.00ct
8.5 × 6.5mm	2.00–2.25ct
9.0 × 7.0mm	2.50ct
10.0 × 7.5mm	3.00ct

Asscher Cut Diamond

Size to Carat Weight Conversion Chart (2mm - 9.5mm)

Size (mm)	Carat Weight (ct)
2.0mm	0.05ct
2.5mm	0.10ct
3.0mm	0.15–0.20ct
3.5mm	0.25–0.28ct
4.0mm	0.35–0.40ct
4.4mm	0.50ct
4.5mm	0.55–0.60ct
5.0mm	0.70–0.75ct
5.5mm	1.00ct
6.0mm	1.25–1.30ct
6.3mm	1.50ct
6.5mm	1.60–1.75ct
7.0mm	2.00ct
7.5mm	2.50ct
8.0mm	3.00ct
8.5mm	3.50ct
9.0mm	4.00–4.50ct
9.5mm	5.00ct

Square Cushion Cut Diamond

Size to Carat Weight Conversion Chart (2mm - 9mm)

Size (mm)	Carat Weight (ct)
2.0mm	0.05ct
3.0mm	0.15–0.20ct
3.5mm	0.25–0.30ct
4.0mm	0.35–0.40ct
4.2mm	0.40–0.45ct
4.5mm	0.50–0.55ct
4.8mm	0.60–0.65ct
5.0mm	0.70–0.75ct
5.2mm	0.80–0.85ct
5.5mm	1.00ct
5.8mm	1.20–1.25ct
6.0mm	1.30–1.40ct
6.3mm	1.50ct
6.5mm	1.60–1.75ct
7.0mm	2.00ct
7.5mm	2.50ct
8.0mm	3.00ct
8.5mm	3.50ct
9.0mm	4.00–4.50ct

Heart Cut Diamond

Size to Carat Weight Conversion Chart

Size (mm)	Carat Weight (ct)
3.5mm	0.18–0.21ct
3.8mm	0.23–0.26ct
4.2mm	0.27–0.29ct
4.5mm	0.30–0.38ct
4.9mm	0.40–0.45ct
5.2mm	0.50–0.57ct
5.5mm	0.60ct
5.8mm	0.70–0.75ct
6.1mm	0.80–0.85ct
6.4mm	1.00–1.10ct
7.0mm	1.20–1.30ct
7.5mm	1.50–1.60ct
8.0mm	1.75–2.00ct
8.5mm	2.25ct
9.0mm	2.50ct
9.5mm	3.00ct
10.0mm	3.50–4.00ct
10.5mm	4.50ct
11.0mm	5.00ct

Baguette Cut Diamond

Size to Carat Weight Conversion Chart

Size (length × width mm)	Carat Weight (ct)
2.5 × 1.5mm	0.04ct
3.0 × 1.5mm	0.05ct
3.5 × 1.5mm	0.07ct
4.0 × 1.5mm	0.09ct
4.0 × 2.0mm	0.12ct
4.5 × 2.0mm	0.13–0.15ct
4.5 × 2.5mm	0.16–0.18ct
5.0 × 2.0mm	0.15–0.18ct
5.0 × 2.5mm	0.20–0.23ct
5.5 × 2.5mm	0.25–0.28ct
6.0 × 2.5mm	0.30–0.35ct
6.0 × 3.0mm	0.35–0.40ct
6.5 × 3.0mm	0.45–0.50ct
7.0 × 3.0mm	0.55–0.60ct
7.0 × 3.5mm	0.65–0.75ct
8.0 × 3.5mm	0.80–0.90ct
9.0 × 4.0mm	1.00–1.20ct

Tapered Baguette Cut Diamond

Size to Carat Weight Conversion Chart

Size (length × width mm)	Carat Weight (ct)
3.0 × 1.5mm	0.04–0.05ct
3.5 × 1.5mm	0.06–0.07ct
4.0 × 1.5mm	0.08–0.09ct
4.0 × 2.0mm	0.10–0.12ct
4.5 × 2.0mm	0.13–0.15ct
4.5 × 2.5mm	0.16–0.18ct
5.0 × 2.0mm	0.15–0.18ct
5.0 × 2.5mm	0.20ct
5.5 × 2.5mm	0.23–0.28ct
6.0 × 2.5mm	0.30–0.35ct
6.0 × 3.0mm	0.35ct
6.5 × 3.0mm	0.40–0.45ct
7.0 × 3.0mm	0.50–0.55ct
7.0 × 3.5mm	0.60–0.70ct
8.0 × 3.5mm	0.75–0.85ct
9.0 × 4.0mm	1.00–1.10ct

Trillion Cut Diamond

Size to Carat Weight Conversion Chart (2.5mm -10mm)

Size (mm)	Carat Weight (ct)
2.5mm	0.05ct
3.0mm	0.09–0.11ct
3.5mm	0.12–0.15ct
4.0mm	0.18–0.25ct
4.5mm	0.23–0.30ct
5.0mm	0.33–0.40ct
5.5mm	0.40–0.50ct
6.0mm	0.60–0.70ct
6.5mm	0.75–0.85ct
7.0mm	1.00–1.20ct
7.5mm	1.30–1.50ct
8.0mm	1.75–2.00ct
8.5mm	2.25ct
9.0mm	2.50ct
9.5mm	3.00ct
10.0mm	3.50–4.00ct

Trilliant Cut Diamond

Size to Carat Weight Conversion Chart (2.5mm – 9mm)

Size (mm)	Carat Weight (ct)
2.5mm	0.05ct
3.0mm	0.09ct
3.5mm	0.15ct
4.0mm	0.20ct
4.5mm	0.30ct
5.0mm	0.36ct
5.5mm	0.56ct
6.0mm	0.70ct
6.5mm	0.90ct
7.0mm	1.10ct
7.5mm	1.40ct
8.0mm	1.80ct
8.5mm	2.20ct
9.0mm	2.50ct

Note: Carat weights are approximate averages and may vary based on exact proportions, depth, cut quality, and individual stone characteristics. Trillion cuts are typically measured point-to-point.