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Ring Size Tool

16.5 mm ring size

The 16.5 mm ring size, measured straight across the inside, is about a US 6. In the UK it is L½, and in Europe 52, and the ring is 51.8 mm round the inside.

16.5 mm ring size in every system

16.5 mm ring size: every system
US and Canadaabout 6
UK, Ireland, AustraliaL½
Europe (EU)52
Japan and China11
India12
Italy, Spain, Switzerland12
Across the inside16.5 mm · 1.65 cm · 0.650 in
Around the inside51.8 mm · 5.2 cm · 2.04 in

Every half millimetre is a little over half a US size, so a 16.0 mm or 17.0 mm ring is the next size down or up. All of these numbers are from the standard ring size conversion table.

See a 16.5 mm ring at its real size

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.

16.5 mm across the inside

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

This size, drawn on your screen

US6

UK L½ · EU 52 · Japan 11 · India 12

16.5 mm (0.65 in) across the inside · 51.9 mm (2.04 in) around

For a wide band (over 4 mm), go up about half a size, to US 6½.

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)
5J½4915.749.3
5¼K5015.950.0
5½K½5116.150.6
5¾L5116.351.2
6L½5216.551.9
6¼M5216.752.5
6½M½5316.953.1
6¾N5417.153.8
7N½5417.354.4

Your questions on a 16.5 mm ring

How long is the inside of a 16.5 mm ring, measured all the way round?

Round the inside it is 51.8 mm, which is 5.2 cm. Straight across, it is 0.65 inches.

Which US ring size matches 16.5 mm across?

It is close to a US 6. In the UK that ring is L½, and in Europe 52.