Moissanite Size & Carat Guide

Each moissanite cut has its own unique dimensions, which means that the same carat weight may appear differently depending on the shape. For reference, here are the most common size and carat pairings available for each cut:

Discover the brilliance of our premium moissanite stones — hand-selected, precision-cut, and ethically crafted to the highest standards. Each stone is D colour, VVS1 clarity, and certified for exceptional quality and light performance. Choose from our curated range of the most popular shapes, or request a custom cut to suit your unique vision.

From classic rounds to striking marquise or radiant cuts, every stone is crafted for fire, brilliance, and long-lasting beauty. Perfect for engagement rings, fine jewellery, or bespoke designs, these moissanites rival the sparkle of natural diamonds while offering outstanding value.

If you're seeking a rare size, ratio, or fancy shape, our team can assist with custom cutting upon request. All moissanites are certified and backed by Diamond Lab’s ethical sourcing and lifetime quality promise.

Understanding Moissanite Sizes & Carat Weights

When selecting your moissanite stone, you’ll notice each shape has its own size-to-carat ratio. This is because different cuts distribute weight differently — for example, a 2.00ct Oval will appear longer than a 2.00ct Round, even though the carat weight is the same.

Rest assured: if you choose a 2.00ct stone, you will receive a 2.00ct stone.
The measurements (e.g. 9×7mm, 8×6mm) are provided as a visual reference only, so you can better understand the proportions of your chosen cut.


What Should I Ask or Consider?

We recommend asking yourself or us:

  • What size looks best for my finger length or ring design?

  • Do I want a larger spread (face-up size) or a more compact cut?

  • Should I prioritise a certain mm size or stick with standard carat weight?

  • Is my setting style better suited to elongated or square proportions?

Not sure? We’re happy to offer personal guidance, just contact us or book a free consultation.


 Custom Cut Available

Looking for a rare dimension or antique-style proportion? We offer custom moissanite cutting to your exact specifications, elongated, chunky, deep, flat, or precision-matched for a setting.

Custom cutting takes approx. 1–2 weeks, and pricing will vary depending on shape and size. Get in touch for a tailored quote.

Round Brilliant
  • 6.5mm – 1.00ct
  • 7.5mm – 1.50ct
  • 8mm – 1.80ct
  • 8.5mm – 2.15ct
  • 9mm – 2.60ct
  • 9.5mm – 3.00ct
  • 10mm – 3.55ct
Oval Brilliant
  • 7x5mm – 1.00ct
  • 7.5x5.5mm – 0.85ct
  • 8x6mm – 1.10ct
  • 9x6.5mm – 1.50ct
  • 9x7mm – 1.60ct
  • 10x7mm – 2.00ct
  • 10.5x7mm – 2.15ct
  • 11x8mm – 2.70ct
  • 12x8mm – 3.10ct
  • 12x9mm – 4.00ct
  • 13x9mm – 4.20ct
  • 14x10mm – 5.40ct
  • 16x11mm – 9.00ct
Cushion Brilliant / Elongated Cushion
  • 5mm – 0.50ct
  • 6.5mm – 1.40ct
  • 7mm – 1.80ct
  • 7.5mm – 2.20ct
  • 8mm – 3.00ct
  • 8.5mm – 3.40ct
  • 9mm – 4.00ct
  • 9.5mm – 4.50ct
  • 10mm – 4.80ct

Elongated Cushion Brilliant

  • 7×5mm – 1.00ct
  • 8×6mm – 1.70ct
  • 9×7mm – 2.30ct
  • 9×7.5mm – 2.50ct
  • 10×8mm – 3.50ct
  • 12×9mm – 5.00ct
  • 13×10mm – 6.00ct
Emerald Cut
  • 7x5mm – 1.10ct
  • 7.5x5.5mm – 1.50ct
  • 8x6mm – 1.75ct
  • 8.5x6.5mm – 2.20ct
  • 9x7mm – 2.75ct
  • 10x8mm – 3.80ct
  • 11x8mm – 5.00ct
  • 12x9mm – 7.00ct
  • 13x10mm – 8.00ct
Elongated Radiant
  • 7x5mm – 1.10ct
  • 7.5x5.5mm – 1.50ct
  • 8x6mm – 1.75ct
  • 8.5x6.5mm – 2.20ct
  • 9x7mm – 2.75ct
  • 10x8mm – 3.80ct
  • 11x8mm – 5.00ct
  • 12x9mm – 7.00ct
  • 13x10mm – 8.00ct
Princess Cut
  • 5.5mm – 0.90ct
  • 6mm – 1.30ct
  • 6.5mm – 1.60ct
  • 7mm – 2.00ct
  • 7.5mm – 2.50ct
  • 8mm – 3.10ct
  • 8.5mm – 3.80ct
  • 9mm – 4.30ct
  • 9.5mm – 5.00ct
  • 10mm – 6.00ct
Asscher Cut
  • 5.5mm – 1.00ct
  • 6mm – 1.25ct
  • 6.5mm – 1.50ct
  • 7mm – 2.00ct
  • 7.5mm – 2.50ct
  • 8mm – 3.00ct
  • 8.5mm – 3.60ct
  • 9mm – 4.20ct
Marquise Cut
  • 8x4mm – 0.50ct
  • 10x5mm – 0.90ct
  • 11x5.5mm – 1.20ct
  • 12x6mm – 1.50ct
  • 13x6.5mm – 2.00ct
  • 14x7mm – 2.50ct
  • 15x7.5mm – 3.00ct
Pear Cut
  • 6x4mm – 0.50ct
  • 8x5mm – 0.80ct
  • 9x6mm – 1.20ct
  • 10x7mm – 1.70ct
  • 11x7.5mm – 2.40ct
  • 12x8mm – 3.00ct
  • 13.5x9mm – 4.00ct
  • 15x10mm – 5.00ct