within · Sizes · updated 9 October 2026

UK ring size W in US sizes and mm

Where a UK W sits on Blue Nile's chart, in every system it prints, with the sizes either side.

Main chart: Blue Nile, read 9 October 2026
Read: 9 October 2026 to 11 October 2026

UK W and the sizes either side

Ring sizes in every system, unisex

Ring sizes in every system, the rows around UK W. From Blue Nile, read 9 October 2026.
US and Canada	UK and Australia	Europe	Japan and Singapore	Inside diameter (mm)
	V	64		20.4
11	V 1/2		23	20.6
	W	65		20.8
11.5	W 1/2	66	24	21
	X			21.2

Source: Blue Nile (bn-dam.services.r2net.com), read 9 October 2026.

UK W at each jeweller

UK W at each jeweller: one row per chart, as each one prints it, with its source and the day it was read.
Maker	US	Europe	Chart	Source
Serge DeNimes	11.5	65	Serge DeNimes ring sizes	Serge DeNimes, 11 October 2026

How to check at home

Lay a ring that already fits on Blue Nile's printed sizer. The circle that just fills the inside of the ring gives the diameter: for a UK W it is the 20.8 mm circle.

Every step, and what to do between two sizes

The sizes either side

Shop in your size

Every piece on within shows the size its boutique printed and how many are left in it.

Each maker's full size chart

Serge DeNimes size chart

The full chart

Sources

Blue Nile: Ring sizes for the US and Canada, the UK and Australia, Europe and Japan by inside diameter, and how to size a ring you already own. bn-dam.services.r2net.com, read 9 October 2026.
Serge DeNimes: The Ring Sizing Guide on Serge DeNimes' Silver Redeemer Ring page: UK, EU and US ring sizes with a finger size in mm. sergedenimes.com, read 11 October 2026.