Wondering how big a 1-carat Marquise Cut Diamond is or how much an 8x4mm Marquise Cut Diamond weighs?

Then you have come to the right page as I have created a full chart and built a really easy-to-use calculator to help you get an idea of how much your Diamond weighs.

Quick Note: These are estimated weights only, the actual weight of your Diamond may be different depending on the proportions of the stone.

Marquise Cut Diamond Weight Calculator

If you have the dimensions of your Diamond, you can use my free calculator below.

The calculator has been designed to automatically calculate the depth of the stone at 60% (which falls in the ideal range) but if you have this measurement, you can enter it in the box.

Marquise Cut Size to Carat Chart

Marquise Cut Diamond

0.5 Carat = 6.6 x 3.3mm

Marquise Cut Diamond

0.75 Carats = 8.2 x 4.2mm

Marquise Cut Diamond

1 Carat = 10.5 x 5.25mm

Marquise Cut Diamond

2 Carat = 13.2 x 6.6mm

Marquise Cut Diamond

3 Carat = 15.0 x 7.6mm

Images are for illustration purposes only as it is very difficult to accurately represent image sizes on screens.

SizeWeight
3×1.5mm0.023ct
3.5×1.75mm0.037ct
4x2mm0.056ct
4.5×2.25mm0.079ct
5×2.5mm0.10ct
5.5×2.75mm0.14ct
6x3mm0.18ct
6.5×3.25mm0.23ct
7×3.50.29ct
7.5×3.750.36ct
8x4mm0.44ct
8.5×4.25mm0.53ct
SizeWeight
9×4.5mm0.63ct
9.5×4.75mm0.74ct
10x5mm0.87ct
11×5.5mm1.15ct
12x6mm1.50ct
13×6.5mm1.91ct
14x7mm2.38ct
15×7.5mm2.93ct
16x8mm3.56ct
17×8.5mm4.27ct
18x9mm5.07ct
20x10mm6.96ct

Creating a chart for Marquise Cut sizes is very difficult due to the different number of length-to-width combinations, which can range from below 1.50:1.0 to more than 2:50:1.0 and this means that there many potential sizes for a 1 carat Marquise Cut Diamond, for example:

  • 1.50:1.0 ratio = 8.6×5.8mm
  • 2.0:1.0 ratio = 10.5X5.25mm
  • 2.5:1.0 ratio = 12×4.9mm

In the chart above, I have used the 2.0:1.0 ratio as most Marquise Cut Diamonds that are available for sale are very close to this length-to-width ratio.

And as with all size-to-weight charts, this should be used as a guide only as there are factors that impact the weight of a Marquise Cut Diamond, including:

  • Girdle thickness
  • Length-to-width ratio
  • Pavilion angle
  • Whether the stone has wide shoulders

Another issue with doing weight estimation for Marquise Cut Diamonds is that there aren’t any globally recognized ‘ideal’ proportions, which is why Marquise Cut Diamonds aren’t given a cut grade by gem labs such as the GIA.

But I do hope that the chart and calculator are helpful in giving you and idea as to how much your Diamond might weigh.

If you want to check the size to weight of other Diamond shapes, then you can use my Diamond weight estimation calculator or check out my other size charts below:

Other Diamond Size Charts