Diamond weight and diamond sizes

The size of a diamond is its weight measured in carats. The more a diamond weighs, the bigger it is.

Play with our Diamond Size Widget below. Discover what different diamond sizes look like on a real hand.

Below are the measurements for the diamonds we sell, which will help you understand diamond sizes.

Please note we always sell as “total diamond weight”. For example, if you buy a pair of earrings, the carats refer to the total diamond weight in the two earrings. If you’re buying a ring with several diamonds, the weight equals the total carats of diamonds in the ring.

If you would like a real sense of scale, follow this link for “real size” images of our diamonds:

round shape diamond
Round Brilliant Cut Diamonds Diameter mm
0.10ct 3.00mm
0.20ct 3.80mm
0.25ct 4.00mm
0.30ct 4.20mm
0.40ct 4.80mm
0.50ct 5.00mm
0.70ct 5.75mm
1.00ct 6.50mm
square shape diamond
Square Princess Cut Diamonds Width mm
0.10ct 2.50mm
0.20ct 3.20mm
0.25ct 3.40mm
0.30ct 3.60mm
0.40ct 4.00mm
0.50ct 4.40mm
0.70ct 4.80mm
1.00ct 5.50mm
emerald shape diamond
Emerald Cut Diamonds Length & Width
0.25ct 4mm x 3mm
0.33ct 5mm x 3mm
0.50ct 8mm x 4mm
1.00ct 10mm x 5mm
pear shape diamond
Pear Shape Diamonds Length & Width
0.30ct 5mm x 3mm
0.50ct 6mm x 4mm
1.00ct 8mm x 5mm
marquise shape diamond
Marquise Diamonds Length & Width
0.25ct 5mm x 3mm
0.50ct 8mm x 4mm
0.75ct 9mm x 4.5mm
1.00ct 10mm x 5mm