SearchDiamond Stud Earrings: What Carat to Buy and How Big It Looks
From the counter at TraxNYC, 47th Street.
The short answer
- On a stud listing the carat is usually for the pair. "2 Ctw" means two carats total weight across both ears, so one carat in each ear. Read the variant: ours say, for example, "1 Carat Each".
- A one-carat round is about 6.5 mm across. Two carats in each ear is about 8.2 mm, by IGI's size chart for round diamonds: twice the weight, not twice the width.
- Choose the size for the ear. One carat or more in each ear shows in conversation; on a small lobe a smaller stone can look in scale. A cluster or halo spreads small diamonds wider than one stone of the same weight.
- We sell lab-grown diamonds and natural diamonds, and every stud on our two stud pages says which. Grade for grade, the same budget buys a bigger pair in lab-grown diamonds, and about nine in ten pairs sold from those pages in the last 90 days were lab-grown diamond studs.
Not sure which size suits you? Talk to a personal jeweler: call 212-872-9692 or send a text, seven days.
On this page: Shop studs Carat per ear Size by carat Lab-grown diamond or natural Shapes Metals and backs How to choose Questions
Carat per ear, or carat for the pair?
Diamond weight is measured in carats. One carat weighs 0.20 grams and divides into 100 points, so a quarter carat is 25 points. GIA separates the two terms buyers mix up: carat weight is the weight of one stone, and total carat weight is every diamond in the piece added together.
On a pair of studs, the number in the title usually counts both ears, as on our round lab-grown diamond studs. Our oval pair says it in its description: 2 ctw, 1 ct each.
The trade word "pointer" follows the same arithmetic: our 25 Pointer studs carry a quarter carat in each ear, half a carat for the pair.
How big each carat looks on the ear
What you see on the ear is the width of the stone face up, in millimeters, not its weight. IGI publishes typical widths for round brilliant diamonds. Here they are read as pairs, beside the round studs we carry at each size.
| Pair (Ctw) | Each ear | About how wide each stone is | On our shelves |
|---|---|---|---|
| 0.20 | 0.10 ct | 3.0 mm | 0.20 Ctw round, lab-grown diamonds |
| 0.40 | 0.20 ct | 3.8 mm | 0.40 Ctw round, lab-grown diamonds |
| 0.50 | 0.25 ct | 4.1 mm | 25 Pointer lab-grown diamond studs |
| 0.60 | 0.30 ct | 4.5 mm | 0.60 Ctw round, lab-grown diamonds |
| 0.80 | 0.40 ct | 4.8 mm | 0.80 Ctw round, lab-grown diamonds |
| 1.00 | 0.50 ct | 5.2 mm | 1 Ctw round, lab-grown diamonds |
| 2.00 | 1.00 ct | 6.5 mm | 2 Ctw round lab-grown diamond studs (the listing states 6.5 mm) |
| 3.00 | 1.50 ct | 7.4 mm | 1.50 ct each lab-grown diamond studs |
| 4.00 | 2.00 ct | 8.2 mm | 4 Ctw round, lab-grown diamonds |
| 6.00 | 3.00 ct | 9.4 mm | 6 Ctw round lab-grown diamond studs (3 carats each) |
Widths from IGI's chart for round brilliant diamonds, face up. Our 1.20, 1.50, 8 and 10 Ctw rounds fall between or past these rows: ask the desk for their measurements.
One stone per ear, drawn to one scale (not life size)
0.25 ct
4.1 mm
0.50 ct
5.2 mm
1.00 ct
6.5 mm
1.50 ct
7.4 mm
2.00 ct
8.2 mm
3.00 ct
9.4 mm
Ten screen pixels for every millimeter of IGI's widths.
Same carat, different size
Two stones of the same weight can face up at different widths. In IGI's words, "Different 1.00 carat diamonds can look different sizes."
Width across the face, in mm: three one-carat round diamonds cut to different depths
Shape moves it too. IGI notes that long shapes such as marquise and pear can look larger than a round of the same weight, while cushion and princess can look smaller from the top; in its example, a 1.06 carat cushion measured 6.33 mm against 6.55 mm for a round of the same weight.
Our own oval pair shows the effect. Each one-carat oval is 8 mm long and 5 mm wide, where a one-carat round is 6.5 mm across.
Clusters and halos look bigger than their weight
A cluster or a halo sets many small diamonds side by side. From our listings' own measurements:
| Pair | Diamonds in the pair | Width of each earring |
|---|---|---|
| 14K gold cluster studs | 1.26 ct, natural diamonds | 10 mm |
| Natural diamond studs | 0.47 ct, natural diamonds | 8 mm |
| 14K gold halo studs | 0.30 ct, natural diamonds | 6 mm |
| Floral Radiance flower studs | 0.25 ct, natural diamonds | 5 mm |
| Round solitaire studs | 2.00 ct, lab-grown diamonds (1 carat each) | 6.5 mm |
A cluster pair of about a carat and a quarter measures 10 mm, wider than a solitaire pair holding two full carats. What you give up is the single large stone: a cluster sparkles as many small points of light, a solitaire as one.
Our best-selling lab-grown diamond and natural diamond studs
Picked from our best sellers over the 90 days to September 26, 2026. Every listing states the origin and the carat weight, most state the grades, and the price is on the listing.
Lab-grown diamond studs
Natural diamond studs
Women's studs Men's stud earrings All women's diamond earrings All men's earrings Lab-grown diamond jewelry
What buyers say about their studs
★★★★★
“I received my oval diamond studs today and they exceeded my expectations, i got a great deal. Amy made the whole process easy and assuring. I'll be ordering more from TraxNYC soon.”
★★★★★
“You actually get what you pay for. I was worried that they were going to be too big and don't even get me started on the packaging. I will be purchasing more in the future”
★★★★★
“Outstanding quality, a product that continues to set itself apart from other Jewelers. My wife absolutely loved them, it was a surprise gift for her, the box presentation was an added bonus and one of the reason that I will purchase again.”
★★★★★
“It came with 2 IGI folders on each lab created diam. The packaging was amazing! A light in the box when opened! …”
★★★★★
“Amazing product!!! Not only is the product exactly what is was advertised as but the buying experience from TRAX NYC was amazing!!!”
★★★★★
“Perfect for people with small ears. They look great with a nice sparkle to them. As far as traxnyc and customer service goes they get five stars. Also fast shipping!”
A few of the five-star reviews buyers left on our listings, chosen by us, quoted as written and trimmed only for length.
Lab-grown diamond or natural diamond?
A lab-grown diamond and a natural diamond are the same material. One formed in the earth and was mined, the other was grown in a laboratory. The listing and its paper tell you which one you are buying.
Our guide to lab-grown diamonds and natural diamonds shows how a gem lab tells them apart and how the two are priced. Here is how the studs on our women's and men's stud pages divide, and what buyers took home.
Natural diamonds Lab-grown diamonds Lab-grown diamond center, natural diamonds around it
Studs on our two stud pages: 53% natural diamonds, 40% lab-grown diamonds, 8% both
Their net sales, last 90 days: 12% natural diamonds, 88% lab-grown diamonds
Their pairs sold, last 90 days: 9% natural diamonds, 91% lab-grown diamonds
Shares of the studs on our women's and men's stud pages, counted September 26, 2026, and of their sales in the 90 days to that date. Rounded, so a row can add to 101.
The ten best sellers on those pages are all lab-grown diamond studs. Studs whose listing names a cut, such as round, Portuguese or oval, are mostly lab-grown diamonds; the classic, black diamond and cluster designs that name no cut are nearly all natural diamonds.
Look wider, at every stud style we list, including the flower, cluster and halo designs whose names say stud, and natural diamonds lead the count at about two in three, with the money split close to even.
Where a stud carries both, a lab-grown diamond center with natural diamonds around it, the listing names each part: read both lines before you buy.
How a machine sorts them. A jeweler cannot tell lab-grown diamonds from natural diamonds by eye, and neither can a pen tester. A screening machine clears or refers each stone, and a gem lab settles it. Watch a screening machine at work on our channel.
A screening machine sorting natural and lab-grown diamonds. 3.7 million views on YouTube, read September 26, 2026.
From the counter
“Choose lab-grown diamonds if you want the look, you do not mind wearing lab-grown, and you would rather put your money into gold or other gems. Choose natural diamonds if the piece is meant to be passed down to someone you love, because that question always comes up.”
Round, Portuguese, oval and the other shapes
Round is the classic stud, and the shape our two stud pages list most.
Round: 45%
Portuguese: 15%
Asscher: 11%
Oval: 6%
Princess: 6%
All other shapes (emerald, cushion, radiant, heart, marquise, clover and more): 17%
Shares of the studs on our two stud pages that name a shape, counted September 26, 2026.
Portuguese cut. Our best-selling stud pair of the last 90 days is a Portuguese cut, the 4 carat lab-grown diamond pair above. Its listing explains the cut: "The Portuguese cut adds extra rows of facets to the plan of a round brilliant, so the face of each stone breaks light into a finer, busier pattern."
The Portuguese studs on our stud pages are lab-grown diamonds, apart from a halo pair that sets a lab-grown diamond center among natural diamonds.
Oval and the others. An oval is longer than it is wide; asscher and princess are square outlines. Across all our stud styles you will also find pear, baguette, and novelty shapes such as hearts, a bull and a butterfly.
Shape changes the look more than the carat does, so if you are between two shapes, ask a jeweler to put both on video for you.
Metals, colors and backs
Metal. About five in six of the studs on our two stud pages that state a metal are 14K gold. Most of the rest are 18K gold, and a few are .925 sterling silver pairs set with lab-grown diamonds. Across every stud style we list you will also find 10K gold and platinum.
Gold color. Our best-selling round and Portuguese-cut lab-grown diamond studs come in yellow, rose or white gold; the oval pair in white or yellow gold; our natural cluster and halo pairs in white or yellow.
Setting. Nearly every stud on the two pages is prong set, and a few are claw or martini set. Prongs, as one of our listings puts it, let light reach the stone from the sides.
The backs. A few of our listings name the back: our Canary VS Studs, our Classic Diamond Stud Earrings, a heart-shape pair in 14K gold and a pear-shape lab-grown diamond pair all say screw backs. Most listings do not say, and some say only "secure posts".
So ask the desk which back your pair comes with and whether it can be changed before you buy. Our Portuguese pair's care note gives good advice for any stud: "check now and then that the backs hold firmly".
What comes with a pair
From our showroom page: "Every purchase comes with an official appraisal: carat and gram weights, diamond grade and color, current market value, and our corporate seal." The exception is silver: "Silver jewelry does not come with an appraisal."
Several of our stud listings add: "At checkout you can add a warranty plan that covers manufacturing defects for 30, 180 or 365 days. Every package ships insured."
One buyer of our one-carat round lab-grown diamond studs wrote that the pair came with IGI folders for each stone. That was one buyer's pair, not a promise for every pair: if you want a lab report with yours, ask the desk before you order.
Talk to a personal jeweler
Ask to see the sizes you are between before you choose.
Our personal jewelers on 47th Street answer by phone and text seven days. Every stone is shown in person or on video before you decide.
How to choose a pair
Choose for the way you will wear them, then for the budget, then for the look.
| If you want | Look at |
|---|---|
| A pair to wear every day | A size you forget you have on, and a harder gold. Our Floral Radiance listing puts it this way: "10K is the hardest of the common gold karats, which suits a pair worn every day." |
| Studs that show in conversation | One carat or more in each ear, 6.5 mm and up (our 2 Ctw listing calls it "a size that shows on the ear in conversation"), or a cluster that spreads 10 mm |
| The most carat for the budget | Lab-grown diamonds; in natural diamonds, a cluster or halo spreads small stones wide |
| A stone formed in the earth | Natural diamonds: our classic studs and our cluster, halo and flower pairs |
| A finer, busier sparkle on a round outline | The Portuguese cut |
| A longer look on the lobe | Oval, pear or marquise |
Budget, stated plainly. Grade for grade, a lab-grown diamond costs a fraction of a natural one, and its price has kept falling, so the same budget buys a bigger pair: our round lab-grown diamond studs run up to 10 carat pairs. A natural diamond is mined and scarce. As our engagement ring guide says, "Neither is the wrong buy."
Grades. Our best-selling lab-grown diamond studs are E or F in color and VS1 in clarity; our natural cluster pair is H-I and SI. For what those letters mean, read our guide to the 4Cs of a diamond.
Size for the ear. Find the width in the size table and hold a ruler to your ear lobe.
Made to order. The whole process behind a pair of diamond studs for a client, and a pair for her daughter. 1.2 million views on YouTube, read September 26, 2026.
Questions we hear at the counter
Do 2 carat diamond studs mean 2 carats in each ear?
Usually not. "2 Ctw" is total carat weight, both ears together, so each stone is one carat. Our listings say it in the variant, for example "1 Carat Each". If a listing is unclear, ask the desk before you pay.
How big is a 1 carat diamond stud?
A one-carat round is about 6.5 mm across, by IGI's size chart and by our own 2 Ctw listing. Cut depth moves it a little: IGI measured three one-carat rounds between 6.25 and 6.65 mm.
What carat studs look good for everyday wear?
For every day, pick a size you forget you have on: a quarter carat in each ear is about 4.1 mm, half a carat about 5.2 mm. One carat in each ear, about 6.5 mm, shows in conversation. If you are between two sizes, call or text a personal jeweler and ask to see both.
Is a lab-grown diamond stud a diamond?
Yes. A lab-grown diamond is diamond, the same carbon crystal as a natural diamond, grown in a laboratory instead of formed in the earth. Every stud on our two stud pages states which it is. Our guide to lab-grown diamonds and natural diamonds explains how the two are told apart.
What kind of backs do your studs have?
A few listings name screw backs; most do not say. Ask the desk which back your pair comes with and whether it can be changed: call or text 212-872-9692.
Do diamond studs come with an appraisal?
Yes, except silver pairs. "Every purchase comes with an official appraisal: carat and gram weights, diamond grade and color, current market value, and our corporate seal." "Silver jewelry does not come with an appraisal."
Can I return a pair of studs?
"Eligible merchandise may be returned within fourteen (14) calendar days of confirmed delivery, as determined by the shipping carrier's delivery confirmation." The policy also says "All approved returns are subject to a non-negotiable 5% restocking fee", and items marked final sale and custom or personalized pieces are not returnable. Read the full refund policy before you order.
Keep reading
More answers from the counter: all TraxNYC buyer's guides.
What buyers say
We have about 4,470 reviews on Google. How to check us: Is TraxNYC legit?
Visit the counter
64 W 47th St, Booth F-1, New York, NY 10036, on 47th Street since 2004. Plan a visit.
Hours
Monday to Friday 11 am to 6 pm ET, Saturday and Sunday 12 pm to 4 pm ET; around a holiday, text first.
Sources
- Sizes by carat, points, and cut depth: IGI, Carat Weight (the size chart for round brilliant diamonds).
- Same carat, different size, and shape: IGI, Advice on carat weight: shape, spread and brightness.
- Carat weight and total carat weight: GIA, Nine things about diamond carat weight, and Diamond Carat Weight.
- What a lab-grown diamond is and how it must be described: FTC, In the Loupe, and the Jewelry Guides, 16 CFR 23.12. Returns: our refund policy.
- Our listings: origin, shape, metal and setting shares counted September 26, 2026 on our women's and men's stud pages; sales shares for the 90 days to September 26, 2026; sizes and grades as each listing states them. YouTube view counts as read September 26, 2026.