US 8.5 to Japan ring size
US ring size 8.5 is Japan 17 — 18.54 mm inner diameter (58.3 mm circumference).
Your size is US 8.5 (UK Q½, EU 58).
Fit confidence Exact table match
Measurement confidence 70/100 · Medium Standard chart conversion; final fit still depends on band width and knuckle shape. Confirm with a printable or physical sizer before ordering an expensive ring.
- US
- 8.5
- UK
- Q½
- EU / ISO
- 58
- Japan
- 17
- CH / IT / ES
- 18
- Ø mm
- 18.54
- Circ mm
- 58.3
| US | UK | EU | JP | CH | Ø mm | Circ mm |
|---|---|---|---|---|---|---|
| 3 | F½ | 44 | 4 | 4 | 14.07 | 44.2 |
| 3.5 | G½ | 45 | 5 | 5 | 14.48 | 45.5 |
| 4 | H½ | 47 | 7 | 7 | 14.88 | 46.8 |
| 4.5 | I½ | 48 | 8 | 8 | 15.29 | 48.0 |
| 5 | J½ | 49 | 9 | 9 | 15.70 | 49.3 |
| 5.5 | K½ | 51 | 10 | 11 | 16.10 | 50.6 |
| 6 | L½ | 52 | 12 | 12 | 16.51 | 51.9 |
| 6.5 | M½ | 53 | 13 | 13 | 16.92 | 53.1 |
| 7 | N½ | 54 | 14 | 14 | 17.32 | 54.4 |
| 7.5 | O½ | 56 | 15 | 16 | 17.73 | 55.7 |
| 8 | P½ | 57 | 16 | 17 | 18.14 | 57.0 |
| 8.5 | Q½ | 58 | 17 | 18 | 18.54 | 58.3 |
| 9 | R½ | 60 | 18 | 20 | 18.95 | 59.5 |
| 9.5 | S½ | 61 | 19 | 21 | 19.35 | 60.8 |
| 10 | T½ | 62 | 20 | 22 | 19.76 | 62.1 |
| 10.5 | U½ | 63 | 22 | 23 | 20.17 | 63.4 |
| 11 | V½ | 65 | 23 | 25 | 20.57 | 64.6 |
| 11.5 | W½ | 66 | 24 | 26 | 20.98 | 65.9 |
| 12 | Y | 67 | 25 | 27 | 21.39 | 67.2 |
| 12.5 | Z | 68 | 26 | 28 | 21.79 | 68.5 |
| 13 | Z½ | 70 | 27 | 30 | 22.20 | 69.7 |
Nearby sizes
| US | Japan | Ø mm |
|---|---|---|
| 8 | 16 | 18.14 |
| 9 | 18 | 18.95 |
Frequently asked questions
What is US 8.5 in Japan ring size?
US ring size 8.5 is Japan 17 (inner diameter 18.54 mm, circumference 58.3 mm).
Is US 8.5 the same as Japan 17?
Yes — a US size 8.5 ring equals Japan 17. They are different scales for the same physical size (18.54 mm inner diameter).
Explore
Ring Size Conversions — All Systems & Sizes · Size 8.5 · See the full international ring size chart