Secret Ring SizeConvert a size
Ring size converter: US, UK and EU
Pick the system you have and the size. A UK N½ is a US 7 and an EU 54; a UK L½ is a US 6 and an EU 52.
The size you have
Right on a size.
Screens, paper and string can be off by a little. Before you order, tell the jeweler how you measured and ask about resizing.
How the three systems line up
US and Canadian sizes are numbers in half sizes, each half size 0.41 mm wider inside. The UK, Ireland and Australia use letters, one letter for about each half US size: a US 7 is an N½, a US 8 a P½. Most of Europe uses the inside circumference in millimeters, rounded: a US 7 is 54.4 mm around, so EU 54.
Because each system rounds differently, two jewelers' charts can differ by about half a size. When you order from another country, give the jeweler the millimeters as well as the size.
Every size side by side is on the ring size chart, and the same sizes in centimeters and inches are on the mm, cm and inches page.
Questions
What is a UK N in US ring size?
A UK N is about a US 6¾ and an N½ a US 7. When in doubt between two, choose the larger.
How do I convert EU ring size to US?
An EU size is the inside circumference in mm. Divide it by 3.1416 for the diameter, or pick it in the converter: EU 54 is a US 7, EU 57 a US 8.
Are Australian ring sizes the same as UK sizes?
Yes, Australia and New Zealand use the same letter sizes as the UK.
Why do conversion charts disagree?
Each system rounds to its own steps, and jewelers' charts round differently. The difference is usually no more than half a size; the millimeters settle it.