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1ct Moissanite Size: Millimeters by Shape (DEW)

What does 1ct moissanite look like in millimeters?

A “1ct” moissanite is usually described by its look and face-up size rather than its actual carat weight, since moissanite and diamond have different densities. In everyday shopping terms, 1ct moissanite typically means “diamond equivalent” sizing (often shown as 1.00ct DEW), which translates to a specific millimeter measurement depending on shape.

Round: the most common 1ct size

A 1ct round moissanite typically measures about 6.5 mm in diameter. Depending on the cutter and the exact proportions (depth, table, and girdle), you may see small variations such as roughly 6.4–6.6 mm.

Popular shapes and their approximate 1ct millimeters

Because shapes spread differently on the finger, “1ct” can look wider or longer even when the overall visual size is similar. Common approximate millimeter sizes for a 1ct diamond-equivalent moissanite include:

Princess (square): about 5.5–5.7 mm
Cushion: about 5.7–6.0 mm (varies by elongated vs. square)
Oval: about 7.5 x 5.5 mm
Pear: about 8.0 x 5.0 mm
Emerald: about 7.0 x 5.0 mm

How it looks on the hand

On most hands, a 1ct round (around 6.5 mm) reads as a noticeable center stone—substantial without looking oversized. Elongated cuts like oval and pear can appear larger than a round because they cover more finger length, even when they’re sold as the same “1ct” equivalent.

Get a closer reference for a certified 1ct moissanite ring

For a concrete example of how a 1ct moissanite is presented in a finished ring—along with details like metal choice and certification—see this guide: certified 1ct moissanite ring in 18K gold.

For 1ct Moissanite Size: Millimeters by Shape (DEW), the best answer depends on fit, material, care instructions, and how the product will be used day to day.

FAQ

Does moissanite look bigger than a diamond of the same carat?

It can, because many sellers use diamond-equivalent sizing and because certain shapes (like oval) have more face-up spread. The best comparison is millimeters, not the printed “ct” label.