Size charts
Earring size chart
A 1 carat round diamond stud measures about 6.4 mm across, and a half-carat stud about 5 mm. Stud pairs are sold by total carat weight, so 1 ct tw means two half-carat studs. Hoops are measured by diameter: huggies are roughly 8 to 12 mm, small hoops 12 to 20 mm, medium 20 to 35 mm, and large hoops start around 40 mm.
Data checked October 5, 2026 against the sources listed below.
Diamond stud size chart (round brilliant)
Diamond stud size chart (round brilliant)
| Carat per stone | Diameter | Range across sources | Stud pair total |
|---|---|---|---|
| 0.10 ct | 3.0 mm | 3.0 mm | 0.20 ct tw |
| 0.125 ct | 3.15 mm | 3.15 mm | 0.25 ct tw |
| 0.16 ct | 3.5 mm | 3.5 mm | 0.32 ct tw |
| 0.25 ct | 4.0 mm | 4.0-4.1 mm | 0.50 ct tw |
| 0.33-0.375 ct | 4.5 mm | 4.5 mm | 0.66-0.75 ct tw |
| 0.50 ct | 5.0-5.1 mm | 5.0-5.1 mm | 1.00 ct tw |
| 0.625-0.65 ct | 5.5 mm | 5.5 mm | 1.25-1.30 ct tw |
| 0.75 ct | 5.8 mm | 5.7-6.0 mm | 1.50 ct tw |
| 1.00 ct | 6.4 mm | 6.3-6.5 mm | 2.00 ct tw |
| 1.25 ct | 6.9-7.0 mm | 6.9-7.0 mm | 2.50 ct tw |
| 1.50 ct | 7.4 mm | 7.3-7.5 mm | 3.00 ct tw |
| 1.75 ct | 7.7 mm | 7.7 mm | 3.50 ct tw |
| 2.00 ct | 8.1 mm | 8.0-8.1 mm | 4.00 ct tw |
| 2.25 ct | 8.5 mm | 8.5 mm | 4.50 ct tw |
| 2.50 ct | 8.7-8.9 mm | 8.7-8.9 mm | 5.00 ct tw |
| 2.75 ct | 9.0 mm | 9.0 mm | 5.50 ct tw |
| 3.00 ct | 9.3 mm | 9.3 mm | 6.00 ct tw |
| 3.25 ct | 9.5 mm | 9.5 mm | 6.50 ct tw |
| 3.50 ct | 9.7-9.75 mm | 9.7-10.0 mm | 7.00 ct tw |
| 3.75 ct | 9.9 mm | 9.9 mm | 7.50 ct tw |
| 4.00 ct | 10.2 mm | 10.1-10.2 mm | 8.00 ct tw |
Hoop earring sizes
| Size | Inches | About the size of | Best for |
|---|---|---|---|
| 8-10 mm | ~3/8 inch | Small shirt button | Subtle, everyday wear; huggie-style hoops |
| 12-15 mm | ~1/2 inch | Standard pencil eraser | Polished daily wear; elevated, minimalist styling |
| 20 mm | ~3/4 inch | Nickel | Versatile size for work or casual outfits |
| 25 mm | ~1 inch | Quarter | Balanced statement; noticeable without feeling oversized |
| 30-35 mm | ~1-1 1/4 inches | Half-dollar | Classic statement hoops; day-to-night wear |
| 40 mm | ~1 1/2 inches | Ping pong ball | Bold styling; events or standout looks |
| 50 mm | ~2 inches | Camera lens cap | Dramatic statement hoops |
| 60 mm | ~2 1/3 inches | Tennis ball | Fashion-forward, high-impact looks |
| 70 mm+ | ~2 3/4 inches | Baseball | Oversized statement, editorial styling |
What hoop size names usually mean
| Name | Approx. diameter | Approx. inches |
|---|---|---|
| Huggie / mini | about 8-12 (core 10-12) mm | about 3/8-1/2 in |
| Small | about 10-20 mm | about 3/8-3/4 in |
| Medium | about 20-35 mm | about 3/4-1 3/8 in |
| Large | about 40 and up mm | about 1 1/2 and up in |
| Oversized / statement | about 50-80+ mm | about 2-3+ in |
How to measure
- 1
Studs: compare against the circles
Print this page at 100% scale and check the 50 mm bar. Each circle is the face-up diameter of a round stud at that size.
- 2
Hoops: measure across
Lay the hoop flat and measure straight across in millimetres. Check whether the seller quotes the inside or the outside diameter.
- 3
Drops: measure from the lobe
Drop earrings typically hang 1 to 3 cm below the earlobe; dangles can reach the jawline or further. Measure from the piercing to the lowest point.
Why two studs of the same carat can look different
Carat is a weight: a metric carat is 200 milligrams. How big a stone looks depends on how it is cut. A deep-cut diamond hides weight below the girdle and faces up smaller; a well-proportioned one spreads the same weight across a wider face. That is why charts disagree by a tenth of a millimetre or two, and why the range column is there.
Frequently asked questions
About 6.4 mm across for a well-cut round brilliant. Depending on cut depth a 1 carat stone can measure roughly 5.6 to 6.6 mm.
Total weight for the pair. 1 ct tw is two studs of about half a carat each, roughly 5.0 to 5.1 mm across.
1 carat total weight, half a carat per earring, is the most popular stud size; most everyday studs fall between 0.25 and 2 carats total.
Huggies typically measure about 8 to 12 mm across, small enough to hug the earlobe.
About 1 inch, roughly the size of a quarter. 50 mm is about 2 inches, a dramatic statement hoop.
Use this chart on your site or listing
Free to embed or print, as long as the credit link to Hues AI stays with it. Copy the code:
Sources
- International Gem Society: standard gem sizes chart
- International Gem Society: what carat diamond should i choose
- The Diamond Pro: carat weight
- Brilliant Earth: carat
- Brilliant Earth: best size diamond stud earrings for everyday
- Brilliant Earth: mm to carat conversion
- Blue Nile: carat size on finger
- GIA: diamond carat weight
- Blue Nile: carat weight
- International Gem Society: estimating gem weight
- Blue Nile: diamond stud earrings guide
- Blue Nile: hoop earring sizes
- Missoma: hoop earrings size guide
- Brilliant Earth: types of hoop earrings
- Brilliant Earth: types of earrings
- Blue Nile: drop vs dangle earrings
- The Diamond Pro: diamond studs vs diamond hoops
- Blue Nile carat size chart (PDF)
- Brilliant Earth carat size guide (PDF)
- Your Diamond Teacher: carat weight
- Blue Nile: stud earrings
- The Diamond Pro: stud earrings
- Blue Nile: drop earrings
- Astrid & Miyu: size guide
- Mejuri: best gold hoop earrings shop
- Mejuri: tube oversized hoops
Related charts & tools
See it worn: Earring virtual try-on
On-ear studs, hoops, and drops rendered in about 30 seconds.
Ring size chart
Ring size chart with US sizes 3 to 13 converted to inner diameter and circumference in mm, UK letters, EU/ISO, Japan and India sizes. Printable at actual size.
Necklace length chart
Necklace length chart from 14 to 36 inches: collar, choker, princess, matinee, opera and rope, where each sits, men's chain lengths, and how to measure.
Watch size chart
Watch size chart: which case diameter suits your wrist, from 34 mm for small wrists to 46 mm and up, plus lug-to-lug, thickness and men's vs women's sizes.
Start with 80 free credits
No card required. Turn your next product shot into catalog-ready imagery in under a minute.