US 10 in every sizing system
| US / Canada | UK / Australia | EU / ISO (circumference, mm) | Japan / Korea | Inside diameter (mm) |
|---|---|---|---|---|
| US 9.5 | S½ | 60.8 | 20 | 19.4 |
| US 10This size | T½ | 62.1 | 21 | 19.8 |
| US 10.5 | U½ | 63.3 | 22 | 20.2 |
What a size 10 ring measures
Inside diameter 19.8 mm (about 0.78 in), inside circumference 62.1 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 10 a common ring size?
Yes. US 10 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 10 in mm?
US 10 is 19.8 mm across the inside and 62.1 mm around the inside. The millimeter circumference is also the EU/ISO size, 62.1.
What is US 10 in UK ring sizes?
US 10 is a UK and Australian T½. UK letters step 1.25 mm of circumference at a time, so a half letter is a real difference.
What is US 10 in EU ring sizes?
US 10 is EU/ISO 62.1. The EU number is the inside circumference in millimeters, so a shop that stocks whole sizes will offer the nearest one.
What is US 10 in Japanese and Korean ring sizes?
US 10 is a Japanese and Korean 21. 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.