Moissanite Size Chart: Carat to MM and DEW

Quick answer: Moissanite is about 10 to 12 percent lighter than diamond, so a moissanite the same size as a 1 carat diamond (about 6.5 mm round) actually weighs roughly 0.88 carat. That is why many sellers describe moissanite by diamond equivalent weight (DEW), meaning the size it matches in diamond terms. When comparing stones, focus on millimeter size, not carats: a 6.5 mm round looks like a 1 carat, 7.5 mm like 1.5 carats, and about 8 mm like 2 carats.

Carat measures weight, not size. Because moissanite is lighter, its carat numbers can be confusing. Here is a simple size chart.

Round Moissanite Size Chart

Diameter	Diamond equivalent (DEW)	Approx. moissanite actual weight
5.0 mm	0.50 ct	About 0.44 ct
6.0 mm	0.75 ct	About 0.66 ct
6.5 mm	1.00 ct	About 0.88 ct
7.5 mm	1.50 ct	About 1.32 ct
8.0 mm	About 2.00 ct	About 1.76 ct
9.0 mm	About 2.75 ct	About 2.40 ct
10.0 mm	About 3.75 ct	About 3.30 ct

Figures are approximate; cut proportions vary slightly. See our diamond size chart for other shapes.

What Is DEW?

Diamond equivalent weight describes the moissanite by the carat weight a diamond of the same size would have. It makes shopping easier because most people think of size in diamond carats. Always check whether a listing shows DEW or actual weight, and compare millimeters to be sure.

Shown: 3.48 Ct Round Cut Fancy Vivid Green Moissanite

Popular Moissanite Sizes

6.5 mm (1 ct DEW): the classic engagement size.
7.5 to 8 mm (1.5 to 2 ct DEW): the most popular moissanite sizes, since larger stones are affordable.
9 mm and up (2.75 ct+ DEW): statement size.

Choosing Size for Your Hand

Slender fingers make stones look larger.
Elongated shapes (oval, pear, marquise) look bigger than rounds of the same weight.
A halo adds visual size.

Read how carat sizes look on the hand.

Moissanite at Ivevar

We list moissanite with clear sizing and hand-set every stone in our Surat workshop. Every piece ships free worldwide, with 30-day easy returns. Browse round moissanite and all loose moissanite.

Shop Loose Moissanite

3.48 Ct Vivid GreenShop Now

3.16 Ct Vivid BlueShop Now

2.98 Ct Intense PinkShop Now

2.81 Ct Vivid PinkShop Now

2.63 Ct Fancy YellowShop Now

2.41 Ct Intense YellowShop Now

Swipe to see more → | View all loose moissanite

Frequently Asked Questions

Is 1 carat moissanite the same size as 1 carat diamond?

No. Moissanite is lighter, so 1 carat of moissanite is slightly larger. Compare millimeters.

What does DEW mean?

Diamond equivalent weight: the diamond carat weight of a stone the same size.

What size moissanite looks like 2 carats?

About 8 to 8.2 mm round.

What is the most popular moissanite size?

Around 1.5 to 2 carats DEW.

Should I shop by mm or carat?

By millimeters; it shows true visible size.

The Bottom Line

Moissanite is lighter than diamond, so compare millimeter size or DEW rather than raw carat weight to know exactly how big your stone will look.

Related Guides

Author Bio

Aumsri Pradhan

Founder, Ivevar Luxury

Aumsri Pradhan is the founder of Ivevar Luxury, a Surat-based fine jewelry brand that designs and handcrafts lab grown diamond and moissanite jewelry in its own workshop. She leads the brand's design and customer experience, from engagement rings and bridal sets to custom pieces made to each client's story. Through the Ivevar blog, she shares practical guidance on lab grown diamonds, moissanite, diamond grading and ring design to help buyers choose with confidence.

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