Ring Size Chart — US, UK, EU, FR & JP (Diameter & Circumference)
Who this is for: For shoppers comparing an international seller's chart, couples sizing secretly, and anyone who wants the whole table on one printable page.
Full US 3–16 chart with UK, EU, French, German and Japanese columns — filter, highlight and print.
Quick answer: US 3–16 spans 44.2–77.3 mm of inside circumference. Key anchors: US 6 = 51.8 mm (UK L½), US 7 = 54.4 mm (N½), US 8 = 56.9 mm (P½), US 9 = 59.5 mm (R½), US 10 = 62.0 mm (T½). Every column below is derived from one formula, so the table is internally consistent.
Show measurements in
mm
Optional — the closest size row lights up so you can read across.
| US | UK | Circumference | Diameter | EU / ISO | FR · IT | JP · CN |
|---|---|---|---|---|---|---|
| 3 | F½ | 44.2 | 14.1 | 44 | 4.1 · 4 | 4 |
| 3.25 | G | 44.8 | 14.3 | 45 | 4.8 · 5 | 5 |
| 3.5 | G½ | 45.4 | 14.5 | 45 | 5.4 · 5 | 5 |
| 3.75 | H | 46.1 | 14.7 | 46 | 6.1 · 6 | 6 |
| 4 | H½ | 46.7 | 14.9 | 47 | 6.7 · 7 | 7 |
| 4.25 | I | 47.3 | 15.1 | 47 | 7.3 · 7 | 7 |
| 4.5 | I½ | 48.0 | 15.3 | 48 | 8 · 8 | 8 |
| 4.75 | J | 48.6 | 15.5 | 49 | 8.6 · 9 | 8 |
| 5 | J½ | 49.3 | 15.7 | 49 | 9.3 · 9 | 9 |
| 5.25 | K | 49.9 | 15.9 | 50 | 9.9 · 10 | 9 |
| 5.5 | K½ | 50.5 | 16.1 | 51 | 10.5 · 11 | 10 |
| 5.75 | L | 51.2 | 16.3 | 51 | 11.2 · 11 | 10 |
| 6 | L½ | 51.8 | 16.5 | 52 | 11.8 · 12 | 11 |
| 6.25 | M | 52.4 | 16.7 | 52 | 12.4 · 12 | 11 |
| 6.5 | M½ | 53.1 | 16.9 | 53 | 13.1 · 13 | 12 |
| 6.75 | N | 53.7 | 17.1 | 54 | 13.7 · 14 | 12 |
| 7 | N½ | 54.4 | 17.3 | 54 | 14.3 · 14 | 13 |
| 7.25 | O | 55.0 | 17.5 | 55 | 15 · 15 | 14 |
| 7.5 | O½ | 55.6 | 17.7 | 56 | 15.6 · 16 | 14 |
| 7.75 | P | 56.3 | 17.9 | 56 | 16.3 · 16 | 15 |
| 8 | P½ | 56.9 | 18.1 | 57 | 16.9 · 17 | 16 |
| 8.25 | Q | 57.5 | 18.3 | 58 | 17.5 · 18 | 16 |
| 8.5 | Q½ | 58.2 | 18.5 | 58 | 18.2 · 18 | 17 |
| 8.75 | R | 58.8 | 18.7 | 59 | 18.8 · 19 | 17 |
| 9 | R½ | 59.5 | 18.9 | 59 | 19.5 · 19 | 18 |
| 9.25 | S | 60.1 | 19.1 | 60 | 20.1 · 20 | 18 |
| 9.5 | S½ | 60.7 | 19.4 | 61 | 20.7 · 21 | 19 |
| 9.75 | T | 61.4 | 19.6 | 61 | 21.4 · 21 | 19 |
| 10 | T½ | 62.0 | 19.8 | 62 | 22 · 22 | 20 |
| 10.25 | U | 62.6 | 20.0 | 63 | 22.6 · 23 | 21 |
| 10.5 | U½ | 63.3 | 20.2 | 63 | 23.3 · 23 | 21 |
| 10.75 | V | 63.9 | 20.4 | 64 | 23.9 · 24 | 22 |
| 11 | V½ | 64.6 | 20.6 | 65 | 24.5 · 25 | 23 |
| 11.25 | W | 65.2 | 20.8 | 65 | 25.2 · 25 | 23 |
| 11.5 | W½ | 65.8 | 21.0 | 66 | 25.8 · 26 | 24 |
| 11.75 | X | 66.5 | 21.2 | 66 | 26.5 · 26 | 24 |
| 12 | X½ | 67.1 | 21.4 | 67 | 27.1 · 27 | 25 |
| 12.25 | Y | 67.7 | 21.6 | 68 | 27.7 · 28 | 25 |
| 12.5 | Y½ | 68.4 | 21.8 | 68 | 28.4 · 28 | 26 |
| 12.75 | Z | 69.0 | 22.0 | 69 | 29 · 29 | 26 |
| 13 | Z½ | 69.7 | 22.2 | 70 | 29.7 · 30 | 27 |
| 13.25 | Z+1 | 70.3 | 22.4 | 70 | 30.3 · 30 | 28 |
| 13.5 | Z+1½ | 70.9 | 22.6 | 71 | 30.9 · 31 | 29 |
| 13.75 | Z+2½ | 71.6 | 22.8 | 72 | 31.6 · 32 | 30 |
| 14 | Z+3 | 72.2 | 23.0 | 72 | 32.2 · 32 | 31 |
| 14.25 | Z+3½ | 72.8 | 23.2 | 73 | 32.8 · 33 | 31 |
| 14.5 | Z+4 | 73.5 | 23.4 | 73 | 33.5 · 33 | 31 |
| 14.75 | Z+4½ | 74.1 | 23.6 | 74 | 34.1 · 34 | 31 |
| 15 | Z+5 | 74.8 | 23.8 | 75 | 34.8 · 35 | 31 |
| 15.25 | Z+5½ | 75.4 | 24.0 | 75 | 35.4 · 35 | 31 |
| 15.5 | Z+6 | 76.0 | 24.2 | 76 | 36 · 36 | 31 |
| 15.75 | Z+6½ | 76.7 | 24.4 | 77 | 36.7 · 37 | 31 |
| 16 | Z+7 | 77.3 | 24.6 | 77 | 37.3 · 37 | 31 |
Every row derives from one formula — circumference = 2.55 × US size + 36.5 — so columns cannot contradict each other.
Core facts
| Chart range | US 3–16 · quarter steps |
|---|---|
| US 6 anchor | 51.8 mm circ · 16.5 mm diam |
| US 7 anchor | 54.4 mm circ · 17.3 mm diam |
| UK scale | BS 6820 letters, ½ steps |
| EU = ISO 8653 | Circumference in mm |
| JP = CN | Same East-Asia numbering |
How do I read this ring size chart?
Find your measurement in the circumference or diameter column and read across. Every row is computed from the US standard formula, so columns agree instead of drifting the way copied-from-copied charts do. The UK column uses the BS 6820 letter scale, EU is the ISO 8653 circumference figure, French and Italian sizes run about 40 lower than ISO, and the Japanese column matches Chinese sizing.
Common uses
- Look up a size between two chart lines (quarter sizes included)
- Decode a Japanese or European seller's size into US terms before checkout
- Print the chart and take it to a jeweller or a partner who is sizing secretly
- Check whether a family heirloom's UK letter maps to a US half size
Frequently Asked Questions
What ring size is 7 cm in the chart?
7 cm of circumference is 70 mm, which lands at US 13¼ (UK Z+1, EU 70). Beware blogs that print 7 cm as US 9 — those tables scale circumference and size with the wrong ratio. Run the number: (70 − 36.5) ÷ 2.55 = 13.1.
Is US ring size the same as UK?
No. US sizes are numbers where one step is 2.55 mm of circumference; UK sizes are letters where one step is about 1.25 mm. US 7 = UK N½, US 8 = UK P½ — every row of this chart shows the pairing.
What is the average ring size on the chart?
Most women fall between US 5 and 8 (average 6–6.5) and most men between US 8 and 12 (average 9–10). If you're secretly sizing a partner, those bands are your safest starting guesses.
Why do charts disagree by half a size?
Because they round differently — some round the diameter first, some the circumference, some drop quarter sizes entirely. This chart computes every column from one formula, so rows can't contradict each other.
More ring size charts
Men's Ring Size Chart
US 8–15 chart for men, with the wide-band and knuckle adjustments that move men's sizes most.
Ring Size Chart in cm
The full chart in centimetres — 4.4 to 7.7 cm circumference with every US and UK equivalent.
Printable Ring Size Chart
A print-ready ring sizer with a credit-card calibration box — print, cut, wrap, read.
Ring Size Conversion Tool
Convert any size between US, UK, EU, French, German, Japanese and Chinese systems — both directions.
Related guides
- How to Measure Ring SizeFour accurate home methods — existing ring, paper strip, calibrated printable, and the gift secret-weapon.
- The Complete Ring Size GuideEvery sizing system explained, quarter sizes, width and knuckle rules, and what resizing costs.
- 7 cm in Ring SizeExactly what 7 cm of circumference converts to — with the math many blogs get wrong.
- Average Ring SizeWhat the average man and woman wear, how build shifts it, and how to guess well for gifts.
- Ring Size 8Everything about US size 8: exact millimetres, international equivalents, and who wears it.