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Ring Size Tool

Ring size 6.5 in mm, cm, UK and EU

Ring size 6½ in the US means a ring 16.9 mm wide inside and 53.1 mm round. The UK calls the same ring M½, Europe 53, Japan 13 and India 13.

Ring size 6.5 in every system

Ring size 6.5 in mm, cm, UK and EU: every system
US and Canada6½
UK, Ireland, AustraliaM½
Europe (EU)53
Japan and China13
India13
Italy, Spain, Switzerland13
Across the inside16.9 mm · 1.69 cm · 0.666 in
Around the inside53.1 mm · 5.3 cm · 2.09 in

One whole size bigger, US 7½, is just under 1 mm wider. All of these numbers are from the standard ring size conversion table.

Check a ring against ring size 6.5 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

Print a sizer

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

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

16.9 mm across the inside

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

This size, drawn on your screen

US6½

UK M½ · EU 53 · Japan 13 · India 13

16.9 mm (0.67 in) across the inside · 53.1 mm (2.09 in) around

For a wide band (over 4 mm), go up about half a size, to US 7.

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 CanadaUK and AustraliaEurope (EU)Inside diameter (mm)Circumference (mm)
5½K½5116.150.6
5¾L5116.351.2
6L½5216.551.9
6¼M5216.752.5
6½M½5316.953.1
6¾N5417.153.8
7N½5417.354.4
7¼O5517.555.1
7½O½5617.755.7

Common questions about ring size 6.5

How many millimetres is US ring size 6½?

It is 16.9 mm wide inside and 53.1 mm round the inside. In inches, the width is 0.67.

How many centimetres is US ring size 6½?

Round the inside it is 5.3 cm, and it is 1.69 cm wide.