Ring size 7.5 in mm, cm, UK and EU

Ring size 7½ in the US means a ring 17.7 mm wide inside and 55.7 mm round. The UK calls the same ring O½, Europe 56, Japan 15 and India 15 to 16.

Ring size 7.5 in every system

Ring size 7.5 in mm, cm, UK and EU: every system
US and Canada	7½
UK, Ireland, Australia	O½
Europe (EU)	56
Japan and China	15
India	15 to 16
Italy, Spain, Switzerland	16
Across the inside	17.7 mm · 1.77 cm · 0.698 in
Around the inside	55.7 mm · 5.6 cm · 2.19 in

One whole size bigger, US 8½, is just under 1 mm wider. All of these numbers are from the standard ring size conversion table.

Check a ring against ring size 7.5 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

US7½

UK O½ · EU 56 · Japan 15 · India 15 to 16

17.7 mm (0.70 in) across the inside · 55.7 mm (2.19 in) around

For a wide band (over 4 mm), go up about half a size, to US 8.

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)
6½	M½	53	16.9	53.1
6¾	N	54	17.1	53.8
7	N½	54	17.3	54.4
7¼	O	55	17.5	55.1
7½	O½	56	17.7	55.7
7¾	P	56	17.9	56.3
8	P½	57	18.1	57.0
8¼	Q	58	18.3	57.6
8½	Q½	58	18.5	58.3

Common questions about ring size 7.5

How many millimetres is US ring size 7½?

It is 17.7 mm wide inside and 55.7 mm round the inside. In inches, the width is 0.70.

How many centimetres is US ring size 7½?

Round the inside it is 5.6 cm, and it is 1.77 cm wide.