Switzerland, Italy and Spain ring sizes
Swiss, Italian and Spanish ring sizes are the ISO circumference minus 40, so ISO 54 is size 14 and ISO 50 is size 10.
Defined by a published formula; the standard text was not read.
Where it is used: Switzerland, Italy, Spain
Switzerland, Italy and Spain size table
| Switzerland, Italy and Spain size | Inside Ø mm | Circumference mm | Nearest US | Nearest UK | Nearest ISO |
|---|---|---|---|---|---|
| 4 | 14.0 | 44.0 | ≈ 3 | ≈ F | 44 |
| 5 | 14.3 | 45.0 | ≈ 3.25 | G | 45 |
| 6 | 14.6 | 46.0 | 3.75 | ≈ H | 46 |
| 7 | 15.0 | 47.0 | ≈ 4 | H½ | 47 |
| 8 | 15.3 | 48.0 | 4.5 | I½ | 48 |
| 9 | 15.6 | 49.0 | ≈ 5 | ≈ J | 49 |
| 10 | 15.9 | 50.0 | 5.25 | K | 50 |
| 11 | 16.2 | 51.0 | ≈ 5.75 | ≈ L | 51 |
| 12 | 16.6 | 52.0 | 6 | L½ | 52 |
| 13 | 16.9 | 53.0 | 6.5 | M½ | 53 |
| 14 | 17.2 | 54.0 | ≈ 6.75 | ≈ N | 54 |
| 15 | 17.5 | 55.0 | 7.25 | O | 55 |
| 16 | 17.8 | 56.0 | ≈ 7.5 | ≈ P | 56 |
| 17 | 18.1 | 57.0 | 8 | P½ | 57 |
| 18 | 18.5 | 58.0 | ≈ 8.5 | Q½ | 58 |
| 19 | 18.8 | 59.0 | 8.75 | ≈ R | 59 |
| 20 | 19.1 | 60.0 | ≈ 9.25 | S | 60 |
| 21 | 19.4 | 61.0 | ≈ 9.5 | ≈ T | 61 |
| 22 | 19.7 | 62.0 | 10 | T½ | 62 |
| 23 | 20.1 | 63.0 | ≈ 10.25 | U½ | 63 |
| 24 | 20.4 | 64.0 | 10.75 | ≈ V | 64 |
| 25 | 20.7 | 65.0 | ≈ 11.25 | W | 65 |
| 26 | 21.0 | 66.0 | 11.5 | ≈ X | 66 |
| 27 | 21.3 | 67.0 | ≈ 12 | X½ | 67 |
| 28 | 21.6 | 68.0 | ≈ 12.25 | Y½ | 68 |
| 29 | 22.0 | 69.0 | 12.75 | ≈ Z | 69 |
| 30 | 22.3 | 70.0 | ≈ 13 | Z+1 | 70 |
| 31 | 22.6 | 71.0 | 13.5 | ≈ Z+2 | 71 |
| 32 | 22.9 | 72.0 | ≈ 14 | Z+2½ | 72 |
About Switzerland, Italy and Spain sizes
Switzerland, Italy and Spain use this ring size system. US 7 corresponds to size 14 in this system and ISO 54, so the local number is smaller than the ISO number. The table shows how a size in one system corresponds to sizes in others.
The system follows ISO circumference, but its numbers are offset: ISO 54 is 14 and ISO 50 is 10. Unlike ISO sizes, these sizes are whole numbers, so a ring between two numbers is rounded. Check how a shop labels and rounds sizes before comparing charts.
Use the table to find the corresponding size in another system, then check the shop’s own chart before buying. If you have a ring that fits, measure its inside diameter or circumference and compare it with the table. You can also use the converter or printable sizer, then confirm the result with the shop’s chart.
Sources
- Ring size (Wikipedia) Checked November 10, 2026
- ISO 8653:2016 Jewellery: Ring-sizes: Definition, measurement and designation (ISO (catalogue page by iTeh Standards)) Checked November 10, 2026