Moissanite Stud Earring Size Guide: Millimetres to Carats
Stud earrings are the easiest moissanite piece to wear every day, but choosing a size online is hard when listings mix millimetres and carats. This guide explains both and shows which sizes suit which look.
Millimetres or carats?
Millimetres (mm) measure the diameter of the stone: the size you actually see on the ear. Carats (ct) measure weight. Moissanite is about 10% lighter than diamond, so moissanite is usually described by its diamond-equivalent weight, the weight a diamond of the same diameter would have. When in doubt, go by millimetres.
Round moissanite size chart
Approximate diamond-equivalent weight per stone, as commonly listed for round brilliant moissanite. A pair has two stones, so a "2 ct pair" usually means two 1 ct studs.
| Diameter | Per stone | Per pair | Look on the ear |
|---|---|---|---|
| 3 mm | 0.10 ct | 0.20 ct | Tiny accent, great for second or third piercings |
| 4 mm | 0.25 ct | 0.50 ct | Subtle everyday sparkle |
| 5 mm | 0.50 ct | 1.00 ct | Classic, noticeable but understated |
| 5.5 mm | 0.60 ct | 1.20 ct | Classic, a little brighter |
| 6 mm | 0.80 ct | 1.60 ct | Popular everyday size |
| 6.5 mm | 1.00 ct | 2.00 ct | The "1 carat stud" look |
| 7.5 mm | 1.50 ct | 3.00 ct | Bold, eye-catching |
| 8 mm | 2.00 ct | 4.00 ct | Statement |
| 9 mm | 3.00 ct | 6.00 ct | Big statement, evening wear |
| 10 mm | 4.00 ct | 8.00 ct | Maximum sparkle |
How to choose
- First moissanite studs: 5–6.5 mm is the sweet spot for most earlobes. It reads as a classic stud without looking oversized.
- Second or third piercings: 3–4 mm keeps a stacked ear balanced.
- Statement or evening: 7.5 mm and up. On smaller earlobes, 8 mm and larger can cover most of the lobe.
- Men's studs: 5–7.5 mm is a common range, depending on how visible you want them.
A quick check at home: measure a pair of studs you already own with a ruler, or compare against the chart above.
Halo and cluster studs look bigger
A halo of small stones around the centre adds a few millimetres to the overall size, so a 6 mm halo stud looks closer to 9 mm across. Flower cluster studs are measured across the whole flower. Our Halo Moissanite Studs list the centre-stone size, and our Flower Moissanite Studs list the overall size.
Huggie hoops
For hoops, the size is the hoop diameter. Our Moissanite Hoops come in 11, 13, 14 and 15 mm: the smaller sizes sit closest to the lobe.
Shop by size
Our Solitaire Moissanite Studs come in ten sizes from 3 mm to 10 mm, in white gold or 14K gold plating, with free shipping. See all moissanite earrings or read our moissanite jewelry guide.