US 12 in every sizing system
| US / Canada | UK / Australia | EU / ISO (circumference, mm) | Japan / Korea | Inside diameter (mm) |
|---|---|---|---|---|
| US 11.5 | W½ | 65.9 | 25 | 21.0 |
| US 12This size | X½ | 67.2 | 26 | 21.4 |
| US 12.5 | Y½ | 68.5 | 27 | 21.8 |
What a size 12 ring measures
Inside diameter 21.4 mm (about 0.84 in), inside circumference 67.2 mm. Measuring a ring that already fits? Measure the inside edge to edge for the diameter. Measuring a finger? Wrap a strip of paper around its base and compare the overlap with the circumference.
Is US 12 a common ring size?
Yes. US 12 sits inside the 8 to 12 range most men's bands are stocked in. Wider bands in this range often need a half size up, so try the actual width.
Between two sizes?
Take the larger one. A ring is easier to make smaller than larger, a wide band needs a little more room than a thin one, and fingers swell in heat and in the evening. A jeweler's sizer set settles it in a minute.
Convert a measurement to a ring size
Measure a ring that already fits the right finger, or the finger itself, and enter the number in millimeters.
Quick answers
Frequently asked questions
What is a US ring size 12 in mm?
US 12 is 21.4 mm across the inside and 67.2 mm around the inside. The millimeter circumference is also the EU/ISO size, 67.2.
What is US 12 in UK ring sizes?
US 12 is a UK and Australian X½. UK letters step 1.25 mm of circumference at a time, so a half letter is a real difference.
What is US 12 in EU ring sizes?
US 12 is EU/ISO 67.2. The EU number is the inside circumference in millimeters, so a shop that stocks whole sizes will offer the nearest one.
What is US 12 in Japanese and Korean ring sizes?
US 12 is a Japanese and Korean 26. Those scales step a third of a millimeter of diameter per number, so they are finer than US half sizes.
Every ring size, US 3 to 13
Conversions are rounded to the nearest standard size, and published charts differ from each other by up to half a size. Treat the result as a close estimate, confirm it with a jeweler's sizer before buying, and check the resizing policy.