Ring Size Chart — International Conversion Table (mm, US, UK, EU, Asia)

Ring Size Chart — International Conversion Table

Use this chart to convert ring sizes between systems — US/Canada, UK/Europe/Australia, Italy/Spain/Switzerland, China/Japan/South America, and India. When getting measured, ask your jeweler for your inside circumference in mm — that's the measurement we work from, and it converts cleanly into any system on this chart.

Need help with how to measure? See our ring size guide for the right way to get an accurate reading and what to do when buying as a surprise.

Take it with you

Download a printable PDF of the full chart — handy when you visit a jeweler to get measured.

⬇ Download PDF Chart

Full Conversion Chart

Inside
Diameter (mm)
Inside
Circumference (mm)
U.S. &
Canada
U.K., Europe
& Australia
Italy, Spain,
Switzerland
China, Japan,
South America
India
12.5 39.1 1 B 1
12.7 39.7 1.25 B.5
12.9 40.4 1.5 C 0.5
13.1 41.0 1.75 C.5 1 1
13.3 41.7 2 D 1.75 2 2
13.5 42.3 2.25 D.5 2.25
13.7 42.9 2.5 E 3 3 3
13.9 43.6 2.75 E.5 3.5 4
14.1 44.3 3 F 4 4
14.3 44.9 3.25 F.5 5.25 5 5
14.5 45.6 3.5 G
14.7 46.2 3.75 G.5 6.5 6 6
14.9 46.8 4 H 7
15.1 47.4 4.25 H.5 7.75 7
15.3 48.1 4.5 I 8 8
15.5 48.7 4.75 I.5 9 9
15.7 49.3 5 J 9
15.9 50.0 5.25 J.5 10 10
16.1 50.6 5.5 K 10
16.3 51.2 5.75 K.5 11.75 11
16.5 51.8 6 L 12.75 11 12
16.7 52.5 6.25 L.5 12
16.9 53.1 6.5 M 14 13 13
17.1 53.7 6.75 M.5
17.3 54.3 7 N 15.25 14 14
17.5 55.0 7.25 N.5 15
17.7 55.6 7.5 O 16.5 15
17.9 56.2 7.75 O.5 16
18.1 56.9 8 P 17.75 16 17
18.3 57.5 8.25 P.5
18.5 58.1 8.5 Q 17 18
18.8 59.1 8.75 Q.5 19 19
19 59.7 9 R 18
19.2 60.3 9.25 R.5 20.25 20
19.4 60.9 9.5 S 19 21
19.6 61.6 9.75 S.5 21.5
19.8 62.2 10 T 20 22
20 62.8 10.25 T.5 21 23
20.2 63.5 10.5 U 22.75 22
20.4 64.1 10.75 U.5 24
20.6 64.7 11 V 23 25
20.8 65.3 11.25 V.5 25
21 66.0 11.5 W 24 26
21.2 66.6 11.75 W.5
21.4 67.2 12 X 27.5 25 27
21.6 67.9 12.25 X.5 28
21.8 68.5 12.5 Y 28.75 26
22 69.1 12.75 Z 29
22.2 69.7 13 Z.5 27 30
22.4 70.4 13.25
22.6 71.0 13.5 31 31

Empty cells indicate no exact equivalent in that system. Use the closest size and confirm with your jeweler. Source measurements rounded to one decimal place.

How to Use This Chart

Find your size in any one column, then read across to see the equivalent in every other system. In Sri Lanka, jewelers may give your size as an inside circumference in mm, a US size, or an Indian size — the system varies by jeweler. Before sharing your size with us, confirm which system your reading is in and use this chart to identify the correct column. We'll handle the conversion from there.

Inside circumference is the distance around the inside of the ring — the same as the circumference of your finger, measured in mm. Inside diameter is the straight-line distance across. Either identifies a size precisely; inside circumference is what we use.

The Colored Stone Co. Note A printed chart isn't a substitute for a proper measurement. Use the chart to convert a size you've already had measured by a jeweler — not to guess your size from a paper ruler. The most common cause of resizing problems is home measurement.

Have a size in one system and want to confirm the conversion before ordering? Send it through and we'll confirm.

💬 Chat with Us on WhatsApp

Frequently Asked Questions

Which column do I use in Sri Lanka?

Sri Lankan jewelers may give your size as an inside circumference in mm, a US size, or an Indian size — it varies by jeweler. Before sharing it with us, confirm which system your reading is in and use this chart to identify the correct column. Make sure you're certain of the size before conveying it to us — we work from whatever measurement you provide.

What's the difference between inside diameter and inside circumference?

Inside circumference is the distance around the inside of the ring — the same as your finger circumference, measured in mm. It's the size we work from and what Sri Lankan jewelers will quote you. Inside diameter is the straight-line measurement across the inside; both identify a size precisely, but circumference (mm) is the one to ask for.

What if my size falls between two rows on the chart?

Round up to the next size, especially for wider bands (4mm and above), which sit tighter on the finger. For narrow bands and rings with intricate settings, message us before deciding — the right call depends on your specific ring style. We're happy to advise.

Can I print the chart?

Yes — use the PDF download button at the top of the page. The PDF is formatted for A4 printing and fits the full chart on a single page, so you can take it with you to a jeweler or keep a copy for reference.