US to UK Ring Size Conversion Guide
TL;DR: The US uses a numerical ring sizing scale; the UK uses an alphabetical scale. A US size 6 is approximately a UK size L, and a US size 9 is approximately a UK size R. Because sizing standards can vary slightly between manufacturers, a direct measurement is always more reliable than a conversion chart alone.
US to UK Ring Size Conversion Chart
| US Size | UK Size (approx.) |
|---|---|
| 3 | F |
| 3.5 | G |
| 4 | H |
| 4.5 | I |
| 5 | J |
| 5.5 | K |
| 6 | L |
| 6.5 | M |
| 7 | N |
| 7.5 | O |
| 8 | P |
| 8.5 | Q |
| 9 | R |
| 9.5 | S |
| 10 | T |
| 10.5 | U |
| 11 | V |
| 11.5 | W |
| 12 | X |
| 12.5 | Y |
| 13 | Z |
Why Sizing Systems Differ
The US system measures ring size on a numerical scale, typically in half-size increments. The UK system uses letters of the alphabet, with each letter representing a small, consistent increase in internal circumference. Both systems ultimately measure the same thing — internal diameter or circumference — just expressed differently.
Why a Chart Alone Isn't Always Enough
Sizing standards can vary slightly between manufacturers and countries, and band width also affects how a given size feels — a wider band generally needs to be sized slightly larger than a narrow band to fit the same finger comfortably. A conversion chart is a solid starting reference, but a direct measurement, ideally professionally taken, is the more reliable route for a piece you'll be commissioning specifically. See our full ring sizing guide for how to measure accurately at home.
Getting an Accurate UK Size
We can supply a ring sizer to measure accurately at home, or advise on converting a size from any other country's system. Get in touch to confirm sizing before a commission begins.
Related Reading
Frequently Asked Questions
What UK ring size is a US size 7? Approximately UK size N, though this can vary slightly depending on band width and the specific sizing standard used.
Are US and UK ring sizes measured the same way? Both ultimately measure internal diameter or circumference, but express the result differently — numerically in the US, alphabetically in the UK.
Last reviewed: July 2026 · À Vie Diamonds