Convert a ring size from one country’s system to another in one step. Choose the system you know, pick your size, and the converter shows the same ring in US, UK, EU/ISO, Indian/Japanese and Swiss sizes, with the inner diameter and circumference. For example, US 7 = UK N½ = EU 54 = India 14 = 17.3 mm.
Ring size conversion chart
The same data as the converter, for every size from US 3 to 15. Diameters follow ISO 8653.
| US / Canada | UK / Australia | EU / ISO | India / Japan | Diameter (mm) | Diameter (in) | Circumference (mm) |
|---|---|---|---|---|---|---|
| 3 | F | 44 | 4 | 14.1 | 0.56 | 44.3 |
| 3.5 | G | 46 | 6 | 14.5 | 0.57 | 45.6 |
| 4 | H | 47 | 7 | 14.9 | 0.59 | 46.8 |
| 4.5 | I | 48 | 8 | 15.3 | 0.60 | 48.1 |
| 5 | J½ | 49 | 9 | 15.7 | 0.62 | 49.3 |
| 5.5 | K½ | 51 | 10 | 16.1 | 0.63 | 50.6 |
| 6 | L½ | 52 | 12 | 16.5 | 0.65 | 51.8 |
| 6.5 | M½ | 53 | 13 | 16.9 | 0.67 | 53.1 |
| 7 | N½ | 54 | 14 | 17.3 | 0.68 | 54.3 |
| 7.5 | O½ | 56 | 15 | 17.7 | 0.70 | 55.6 |
| 8 | P½ | 57 | 16 | 18.1 | 0.71 | 56.9 |
| 8.5 | Q½ | 58 | 18 | 18.5 | 0.73 | 58.1 |
| 9 | R½ | 60 | 19 | 19.0 | 0.75 | 59.7 |
| 9.5 | S½ | 61 | 20 | 19.4 | 0.76 | 60.9 |
| 10 | T½ | 62 | 21 | 19.8 | 0.78 | 62.2 |
| 10.5 | U½ | 63 | 23 | 20.2 | 0.80 | 63.5 |
| 11 | V½ | 65 | 24 | 20.6 | 0.81 | 64.7 |
| 11.5 | W½ | 66 | 25 | 21.0 | 0.83 | 66.0 |
| 12 | X½ | 67 | 26 | 21.4 | 0.84 | 67.2 |
| 12.5 | Z | 68 | 27 | 21.8 | 0.86 | 68.5 |
| 13 | Z+1 | 70 | 29 | 22.2 | 0.87 | 69.7 |
| 13.5 | Z+2 | 71 | 30 | 22.6 | 0.89 | 71.0 |
| 14 | Z+3 | 72 | 31 | 23.0 | 0.91 | 72.3 |
| 14.5 | Z+4 | 74 | 32 | 23.4 | 0.92 | 73.5 |
| 15 | Z+5 | 75 | 33 | 23.8 | 0.94 | 74.8 |
Most searched conversions
| Conversion | Answer |
|---|---|
| US 5 to UK | UK J½ (15.7 mm, EU 49) |
| US 6 to UK | UK L½ (16.5 mm, EU 52) |
| US 7 to UK | UK N½ (17.3 mm, EU 54) |
| US 8 to UK | UK P½ (18.1 mm, EU 57) |
| US 9 to UK | UK R½ (19.0 mm, EU 60) |
| US 10 to UK | UK T½ (19.8 mm, EU 62) |
| UK L to US | about US 5¾; UK L½ is US 6 |
| UK N to US | about US 6¾; UK N½ is US 7 |
| UK P to US | about US 7¾; UK P½ is US 8 |
| EU 52 to US | US 6 (51.8 mm around) |
| EU 54 to US | US 7 (54.3 mm around) |
| EU 57 to US | US 8 (56.9 mm around) |
| India 12 to US | US 6 (16.5 mm) |
| India 14 to US | US 7 (17.3 mm) |
| India 16 to US | US 8 (18.1 mm) |
How each ring size system works
US and Canada
Numbers from about 3 to 15, in half and quarter sizes. Each whole size adds about 0.81 mm of inner diameter (2.55 mm of circumference). Mexico and much of South America use the same scale.
UK, Ireland, Australia and New Zealand
Letters from A to Z, with half sizes such as N½. Each letter adds about 1.25 mm of circumference (0.4 mm of diameter), roughly half a US size. Sizes above Z are written Z+1, Z+2 and so on.
EU and ISO (Germany, France, Italy, Spain, Netherlands)
The inner circumference in millimetres. EU 54 is a ring 54 mm around the inside. Because it is a measurement rather than a code, it is the easiest system to convert from: divide by 3.1416 for the diameter.
India, Japan, China and Pakistan
Whole numbers from 1 upward. Size 1 is a 13 mm inner diameter and each number adds one third of a millimetre. Indian size 14 is 17.3 mm, the same as US 7. Local jewellers in Pakistan use the same scale; see the ring size chart for Pakistan.
Switzerland
The EU circumference minus 40. EU 54 is Swiss 14, EU 57 is Swiss 17. Many Swiss watch and jewellery brands use this scale.
Why conversions are sometimes off by a quarter size
Each system rounds differently. A UK half letter and a US quarter size are both about 0.2 mm of diameter and an Indian number is 0.33 mm, but they do not line up exactly, so one UK size can fall between two US sizes. Brands also differ slightly in how they cut their mandrels. When the converter shows a size between two of yours, or a shop’s chart disagrees with this one by a quarter size, trust the diameter in mm: ask the seller for the inner diameter of their size and compare it with a ring you already own, measured with the ring size calculator or the on-screen sizer.
Buying a ring from another country
- From the US (Amazon, Etsy, US brands): use the US column. Quarter sizes are common.
- From the UK or Australia: use the letter column; half letters are standard in UK jewellers.
- From Europe: use the EU number, which is the circumference in mm.
- From India, Pakistan or the Gulf: local shops use the India/Japan number; international brands there use US or EU sizes.
- Resizing: most plain gold and silver bands can be resized one or two sizes. Eternity rings, tungsten and titanium usually cannot, so convert carefully before ordering.
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Open the free ring sizer →Frequently asked questions
How do I convert a US ring size to UK?
Use the converter or chart: US 6 is UK L½, US 7 is UK N½, US 8 is UK P½, US 9 is UK R½ and US 10 is UK T½. One US size is about two UK letters.
What is a size 7 ring in Europe?
US 7 has a 54.3 mm inner circumference, so it is EU 54 (Swiss 14).
Is UK size N the same as US 7?
Almost. UK N is about US 6¾ and UK N½ is US 7. If a UK shop only offers whole letters, choose N for a snug fit or O for a looser fit.
What is Indian ring size 12 in US size?
Indian size 12 is a 16.5 mm inner diameter, which is US 6 and UK L½.
Are ring sizes the same for men and women?
Yes. Ring sizes measure the inside of the ring, so the same chart applies to everyone. Men simply tend to wear larger sizes (US 9–11) than women (US 5–7).