Ring size 11.5 in mm, cm, UK and EU

Ring size 11½ in the US means a ring 21.0 mm wide inside and 65.9 mm round. The UK calls the same ring W½, Europe 66, Japan 24 and India 26.

Ring size 11.5 in every system

Ring size 11.5 in mm, cm, UK and EU: every system
US and Canada	11½
UK, Ireland, Australia	W½
Europe (EU)	66
Japan and China	24
India	26
Italy, Spain, Switzerland	26
Across the inside	21.0 mm · 2.10 cm · 0.826 in
Around the inside	65.9 mm · 6.6 cm · 2.59 in

One whole size bigger, US 12½, is just under 1 mm wider. All of these numbers are from the standard ring size conversion table.

Check a ring against ring size 11.5 on your screen

1Match a bank card

The card works like a ruler: nothing on it is read or saved, and a driving licence works too. Only its height counts, so the drawing may run off the edge of a phone. Hold the card flat on the screen, long side across, with its top edge on the drawing's top line. Then move the slider until the drawing's bottom line meets the card's bottom edge.

Optional. Only needed to lay a ring or strip on the screen; typed measurements work without it. Nothing on the card is read or saved.

2Measure

A ring I own My finger Print a sizer

Inside diameter of your ring mm

Lay the ring on the circle, or type the inside diameter if you measured it.

Length of your paper strip mm

Wrap a thin strip of paper around the base of your finger, mark where it overlaps, then measure to the mark.

The circle shows a 17.3 mm ring, drawn for a typical screen.

This size, drawn on your screen

US11½

UK W½ · EU 66 · Japan 24 · India 26

21.0 mm (0.83 in) across the inside · 65.9 mm (2.59 in) around

For a wide band (over 4 mm), go up about half a size, to US 12.

See every size in the ring size chart · Convert a size you already know

Nearby sizes

Too tight or too loose? Try the size one row up or one row down.

Nearby sizes
US and Canada	UK and Australia	Europe (EU)	Inside diameter (mm)	Circumference (mm)
10½	U½	63	20.2	63.4
10¾	V	64	20.4	64.0
11	V½	65	20.6	64.6
11¼	W	65	20.8	65.3
11½	W½	66	21.0	65.9
11¾	X	67	21.2	66.6
12	X½	67	21.4	67.2
12¼	Y	68	21.6	67.8
12½	Y½	68	21.8	68.5

Common questions about ring size 11.5

How many millimetres is US ring size 11½?

It is 21.0 mm wide inside and 65.9 mm round the inside. In inches, the width is 0.83.

How many centimetres is US ring size 11½?

Round the inside it is 6.6 cm, and it is 2.10 cm wide.