Size 66 ring in US and UK sizes

Size 66 ring, as Europe counts it, means 66 mm round the inside, or 21.0 mm wide. In the US it is about a 11½, and in the UK W½.

Size 66 ring in every system

Size 66 ring in US and UK sizes: every system
US and Canada	about 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 · 0.827 in
Around the inside	66.0 mm · 6.6 cm · 2.60 in

Each European size is 1 mm bigger round than the one before, and 66 mm is the same as 6.6 cm. All of these numbers are from the standard ring size conversion table.

Check a ring against a size 66 ring 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 a size 66 ring

How many millimetres is a size 66 ring?

It is 21.0 mm wide inside and 66.0 mm round the inside. In inches, the width is 0.83.

How many centimetres is a size 66 ring?

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