Home Stud Earrings Size Guide

VVS+ Lab-Grown Diamond Studs · SEEPZ Direct

Carat is weight, not size.
Here's what each weight actually looks like.

Every carat weight has a real mm diameter. See it at true scale next to a reference object, pick your setting, compare two sizes side by side. No guessing.

Diameter values from GIA round brilliant standard reference. Source: gia.edu ↗

See it at actual size

The SVG below renders at 96 CSS dpi — 1mm = 3.7795px. A US dime is 17.91mm; if the reference dime in the visualizer matches a real dime held against your screen, the diamond circles are calibrated.

Note: Retina and HiDPI displays render CSS pixels at the same physical size as standard screens (the browser compensates). Results accurate on laptop/desktop; phone screens held close may look slightly larger in person.

Reference: US dime = 17.91 mm diameter. Hold a real dime against the screen to verify calibration.

Round brilliant — carat to mm chart

Each value is the average girdle diameter for an ideal-cut round brilliant. Earring carat weights are listed as pair totals — each earring is half the listed weight.

"Face-up size" is what you see looking straight at the diamond. An ideal cut maximises the face-up diameter for a given weight. Deep or shallow cuts can measure the same mm but look visually different.

Pair weight Per ear Diameter (mm) Scale Martini from
1 ct pair 0.5 ct/ear 5.2 mm
$1,107
1.5 ct pair 0.75 ct/ear 5.9 mm
$1,589
2 ct pair 1 ct/ear 6.5 mm
$2,167
3 ct pair 1.5 ct/ear 7.4 mm
4 ct pair 2 ct/ear 8.1 mm
Source: GIA round brilliant average girdle diameter, ideal cut (depth ~61–62%). gia.edu ↗

Why face-up size differs from carat weight

Carat is pure mass — 0.2 grams per carat. A deep-cut diamond and a shallow-cut diamond at the same carat weight have very different face-up appearances because the stone's proportions determine how much of that mass lives below the girdle (invisible in a setting) versus above it (what you see).

Three factors govern how large a diamond looks face-up for a given carat weight:

Cut depth %

Ideal-cut rounds land at 61–62% depth. Deeper cuts hide mass below the girdle — smaller face-up diameter for the same carat. Shallow cuts spread wide but lose brilliance. GIA Excellent cut grade targets the proportions that optimise both.

Setting choice

The 3-Prong Martini covers less of the girdle edge — marginally more face-up diamond visible. The 4-Prong TS4P raises the diamond higher off the lobe, increasing perceived presence and scintillation, though the face-up mm is identical to the Martini for the same stone.

Color grade

This doesn't change mm, but it changes perceived size at a table. E-F colorless diamonds appear to "bloom" more in light — the face-up area looks slightly larger than a J or K color stone of identical diameter because the contrast between facets is crisper. StudsDirect sources E-F minimum.

Clarity

VVS+ clarity means no inclusions visible at 10x magnification. Face-up, a VVS stone is optically clean — light enters and exits without scatter from inclusions. VS2 or SI stones let inclusions interrupt light paths, creating the perception of a slightly smaller, cloudier face. VVS is the floor, not the ceiling.

Compare two sizes

Select any two carat weights to see them side by side at true mm scale.

The 1.5ct sweet spot

Why we removed sub-1.5ct from the lineup

Visible presence without the natural-diamond price tax.

A 1ct pair (0.5ct/ear) measures 5.2mm per diamond. Elegant, classic, understated. In natural diamond, 1ct total is the entry-point where pricing exponentiates — you pay a scarcity premium that has nothing to do with the stone's optical properties.

In lab-grown, that scarcity premium is gone. A 1.5ct pair (0.75ct/ear, 5.9mm) costs $1,589 in the Martini — less than many 0.5ct natural-diamond options at comparable clarity and color. The 0.7mm of extra diameter is immediately visible. The difference in presence is real and significant at conversational distance.

We stock 1ct because customers ask. But 1.5ct is the recommendation. It's where the VVS+ E-F combination stops looking "fine" and starts looking statement.

Shop the collection

All sizes. VVS+ E-F IGI-certified. 14K solid gold. SEEPZ-sourced, direct from manufacturer. Prices verified May 2026.

1 ct pair 5.2 mm per diamond · 0.5 ct/ear from $1,107 Shop →
1.5 ct pair 5.9 mm per diamond · 0.75 ct/ear from $1,589 Shop →
2 ct pair 6.5 mm per diamond · 1 ct/ear from $2,167 Shop →

Common questions

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