Jewelry Size & Fit Guide
Every piece we sell is made or finished in our Troy showroom, so we can size almost anything. Use the guides below to measure at home — then come in or call (248) 585-4447 and we'll confirm it on a professional mandrel before your piece is finished.
Ring Sizes
US sizes with inside diameter and circumference, plus UK, EU and Japan equivalents.
| US | Inside diameter (mm) | Inside circumference (mm) | UK / AU | EU | Japan |
|---|---|---|---|---|---|
| 3 | 14.1 | 44.3 | F | 44 | 4 |
| 3½ | 14.5 | 45.5 | G | 45 | 5 |
| 4 | 14.9 | 46.8 | H | 47 | 7 |
| 4½ | 15.3 | 48.0 | I | 48 | 8 |
| 5 | 15.7 | 49.3 | J | 49 | 9 |
| 5½ | 16.1 | 50.6 | K | 50 | 10 |
| 6 | 16.5 | 51.9 | L | 51 | 12 |
| 6½ | 16.9 | 53.1 | M | 53 | 13 |
| 7 | 17.3 | 54.4 | N | 54 | 14 |
| 7½ | 17.7 | 55.6 | O | 55 | 15 |
| 8 | 18.1 | 57.0 | P | 57 | 16 |
| 8½ | 18.5 | 58.1 | Q | 58 | 17 |
| 9 | 19.0 | 59.5 | R | 59 | 18 |
| 9½ | 19.4 | 60.9 | S | 60 | 19 |
| 10 | 19.8 | 62.1 | T | 62 | 20 |
| 10½ | 20.2 | 63.5 | U | 63 | 21 |
| 11 | 20.6 | 64.6 | V | 64 | 22 |
| 11½ | 21.0 | 66.0 | W | 65 | 23 |
| 12 | 21.4 | 67.2 | X | 67 | 24 |
| 12½ | 21.8 | 68.5 | Y | 68 | 25 |
| 13 | 22.2 | 69.7 | Z | 69 | 26 |
| 13½ | 22.6 | 71.0 | Z+1 | 70 | 27 |
Sizes above US 13½ are not covered by published industry charts. We size those in person on a mandrel — call us and we'll take care of it.
Ring size charts are accurate to roughly ±0.2 mm. Reference: GIA ring size chart and Tiffany & Co. size guide.
How To Measure Your Ring Size At Home
String or paper method
- Wrap a strip of paper or a piece of string snugly around the base of your finger.
- Mark where the two ends meet.
- Measure that length in millimeters and match it to the inside circumference column above.
- If you land between two sizes, choose the larger size.
Measure a ring you already own
Measure the inside diameter of a ring that fits the correct finger, then match that number to the inside diameter column above.
Get it right the first time
- Measure in the afternoon or evening. Fingers are at their smallest first thing in the morning.
- Measure at normal room temperature. Cold shrinks fingers; heat, salt, alcohol, caffeine and exercise swell them. Wait about an hour after any of those.
- Measure two or three times on different days and use the larger reading if they disagree.
- Size up for wide bands. A 6 mm band fits tighter than a 2 mm band at the same nominal size.
- Printable sizers: print at 100% scale, never "fit to page," and check the printed scale against a credit card before trusting it.
- Paper and string carry about ±0.3–0.5 mm of error. Treat a home measurement as a strong starting point, not a final answer.
Sources: Blue Nile, Tiffany & Co.
Wedding & Anniversary Band Widths
| Style | Typical width | Most popular | Comfort fit |
|---|---|---|---|
| Women's wedding band | 1.5–4 mm | 2–3 mm | Optional below 4 mm |
| Women's engagement ring band | 1.5–2.5 mm | 2 mm | — |
| Men's wedding band | 5–8 mm | 5–6 mm | Recommended at 4 mm and up |
A comfort-fit band has a domed interior instead of a flat one, which glides on more easily. Comfort-fit bands generally run about a half size smaller than the flat-fit equivalent — but very wide bands near 8 mm can sit tighter than expected, so try a physical comfort-fit sizer before ordering.
Sources: Brilliant Earth width chart, Thorum comfort-fit guide.
Necklace & Chain Lengths
| Style | Inches | Centimeters | Where it sits |
|---|---|---|---|
| Collar | 12–14" | 30–36 cm | Directly against the throat |
| Choker | 14–16" | 36–41 cm | Base of the neck, at the collarbone |
| Princess | 18" | 46 cm | At or just below the collarbone |
| Matinee | 20–24" | 51–61 cm | At or above the bust |
| Opera | 28–36" | 71–91 cm | At or below the bust |
| Rope | 36"+ | 91 cm+ | Below the bust; can be doubled or knotted |
To measure: wrap a string or tape measure around your neck where you want the chain to sit, then add 2–4 inches depending on how much drape you want. For layering, step each chain 2 inches apart so pendants don't collide.
Sources: JBR Jeweler, Gabriel & Co.
Bracelet Sizes
Measure your bare wrist just below the wrist bone, then use the table below.
| Wrist | Bracelet length (comfort fit) | Fit |
|---|---|---|
| 5.5–6.0" (14.0–15.2 cm) | 6.5–7.0" | Small |
| 6.0–6.5" (15.2–16.5 cm) | 7.0–7.5" | Medium |
| 6.5–7.0" (16.5–17.8 cm) | 7.5–8.0" | Large |
| 7.0–7.5" (17.8–19.1 cm) | 8.0–8.5" | X-Large |
Allowance: add ¼–½" for a snug fit, ¾–1" for a comfort fit, 1–1¼" for a loose, dangling fit. Charm bracelets want the full 1" so charms have room to hang.
Typical lengths: women's run 6.5–7.5" with 7" most common. Men's run 7.5–9" with 8" most common.
Cuffs are sized by opening, not circumference: under 2.5" opening is small, 2.5" and over is medium.
Bangles
A bangle has to clear the widest part of your hand across the knuckles, not just your wrist — so it needs more room than a clasped bracelet.
| Wrist | Bangle inner circumference | Bangle inner diameter |
|---|---|---|
| 5.0–5.5" | 5.7–6.1" | 48–51 mm |
| 5.5–7.0" | 6.5–6.9" | 54–57 mm |
| 7.0–8.0" | 7.2–7.7" | 60–64 mm |
| 8.5–9.0" | ~8.2" | ~67 mm |
Sources: James Avery, OOTB Jewelry, The Jewellery Room.
Hoop Earring Sizes
Hoops are measured by inner diameter. Hold a coin up to your ear to picture the scale.
| Diameter (mm) | Inches | About the size of | Category |
|---|---|---|---|
| 10 mm | 3/8" | Thumbtack head | Extra small |
| 15 mm | 1/2" | Dime | Extra small |
| 20 mm | 3/4" | Penny | Small |
| 25 mm | 1" | Quarter | Small |
| 30 mm | 1¼" | Half dollar | Medium |
| 40 mm | 1½" | Ping pong ball | Medium |
| 50 mm | 2" | Golf ball | Large |
| 60 mm | 2⅜" | Billiard ball | Large |
Sources: Borsheims, Ezra Gems.
Still Not Sure?
Don't guess on a piece this important. Text or call (248) 585-4447, or book an appointment and we'll size you in the showroom in about two minutes. We also size most rings we sell after purchase — ask us about it.