Ring Size Guide for All Countries – UK, US, EU, Japan, India & More 2026

Ring Size Guide for All Countries – UK, US, EU, Japan, India & More (2026)

The complete ring size guide for all countries in 2026 — instantly convert between UK, US, EU/ISO, Japanese, Chinese, Indian, Australian, Swiss, French, Italian, and Spanish ring sizes. Free international calculator, full conversion chart, and expert sizing tips for every system.

🇬🇧 UK A–Z+2 🇺🇸 US 1–13 🇪🇺 EU / ISO MM 🇯🇵 Japan 1–30 🇮🇳 India 1–30 🇨🇳 China 1–33 🇦🇺 Australia 🇨🇭 Swiss 🇫🇷 French / Italian 🧮 Free Calculator 📅 2026 Updated

Ring Size Guide for All Countries – One Universal Anchor

Every ring sizing system in the world is anchored to the same two measurements: the inner circumference of the ring in mm (the number the EU/ISO system uses directly) and the inner diameter in mm. Once you know either of those two numbers, you can convert to any country's sizing system — UK letters, US decimal numbers, Japanese integers, Indian numbers, Chinese numbers, Swiss numbers, or French/Italian numbers. The full conversion chart below covers all 10 major systems side-by-side for every UK size A through Z+2.

🇬🇧 UK Letters 🇺🇸 US Numbers 🇪🇺 EU / ISO MM 🇯🇵 Japan 🇮🇳 India 🇨🇳 China 🇦🇺 Australia 🇨🇭 Swiss

10+

🌍 Country Sizing
Systems Covered

📐 Universal Anchor
Used by All Systems

UK M

👩 = US 6 = EU 53
= JP 12 = IN 12

UK T

👨 = US 9.625
= EU 61 = JP 20

🌍

Ring Size Guide for All Countries – Why Conversions Matter (2026)

With so much jewellery now bought online from international retailers — US brands on Etsy, Japanese ring brands, Indian gold jewellers, European designers — knowing how to convert ring sizes across all countries is essential before purchasing. A UK M is not the same as typing "M" into a US or Japanese retailer's size selector. This ring size guide for all countries gives you the exact equivalent in every major system, so you can order with confidence from any retailer anywhere in the world.

🌍 Ring Sizing Systems Around the World – Complete Guide

🇬🇧

UK & Ireland

Alphabetical letters A through Z+2. Each step ≈ 1.25mm circumference. Most common women's size: M. Most common men's size: T.

Letter System

🇦🇺

Australia & New Zealand

Uses the same letter system as the UK — A through Z+2 with identical measurements. A UK M = Australian M. Direct conversion with no adjustment needed.

Same as UK

🇺🇸

USA & Canada

Decimal numbers from 1 to 13, including half sizes (e.g. 6.5, 7.5). No letters. UK M = US 6. UK T = US 9.625. The most common women's US size is 6–7.

Number System

🇪🇺

Europe / ISO

Uses the inner circumference in mm directly as the size number — the most logical system globally. EU 53 = 53mm inner circumference = UK M. Used across Germany, Netherlands, Scandinavia, and most EU countries.

Circumference MM

🇫🇷

France & Italy & Spain

French/Italian system = inner circumference in mm minus 40. So a 52mm circumference ring = French size 12 (52 − 40 = 12). UK M (52.5mm) = French 12–13. Also used in Spain, Portugal, and parts of South America.

Circ. MM − 40

🇨🇭

Switzerland

Swiss sizing = inner circumference in mm minus 40, same formula as the French system. Swiss size 13 = 53mm = UK M. Ranges from approximately 1 to 27 for most adult sizes.

Circ. MM − 40

🇯🇵

Japan

Japanese sizes run from 1 to 30 and use a separate integer scale based on inner circumference. JP size 12 = UK M = US 6 = EU 53. The Japanese system has smaller increments between sizes than the UK system.

JP Number Scale

🇰🇷

South Korea

Korean ring sizes use the same integer scale as Japan. KR 12 = JP 12 = UK M. Direct equivalence with the Japanese sizing table in most cases. Verify with the retailer as some Korean brands use EU sizing.

Same as Japan

🇮🇳

India

Indian ring sizes use a number scale from 1 to 30, broadly equivalent to the Japanese scale. IN size 12 ≈ UK M = US 6. However, Indian jewellers may use slightly different internal scales — always confirm with the specific retailer.

Number Scale

🇨🇳

China

Chinese sizing runs from approximately 1 to 33 on a number scale based on inner circumference. CN size 12 ≈ UK M. Chinese online retailers (Alibaba, Taobao) may also list sizes in mm diameter — always check which system the listing uses.

Number Scale

🇷🇺

Russia

Russian ring sizing uses the inner diameter in mm as the size number. Russian size 17 = 17mm inner diameter = UK M (16.7mm ≈ 17). Rounds to nearest whole mm. Easy to convert — just use the Diam.(MM) column in the chart below.

Diameter MM

🇩🇪

Germany & Austria

Germany and Austria use the EU/ISO system — inner circumference in mm. Same as the EU column in the chart below. German size 53 = UK M. Easy to verify — just look at the EU column.

Same as EU/ISO

🔢 Ring Size Conversion Formulas – All Countries

EU / ISO → UK Letter

Find EU number in Circ.(MM) column → read UK letter

EU 53 = 53mm circumference → UK M. EU uses circumference directly.

French / Italian / Swiss → MM

Add 40 to the French/Swiss size number to get circumference in mm

French 13 + 40 = 53mm = EU 53 = UK M. Subtract 40 to convert back.

Russian Size → UK Letter

Russian size = inner diameter in mm → find in Diam.(MM) column

Russian 17 = 17mm diameter ≈ UK M (16.7mm). Rounds to nearest whole mm.

Diameter ↔ Circumference (All Countries)

Circ. = Diameter × π (3.1416) | Diameter = Circ. ÷ π

This formula converts between any diameter-based (Russian) and circumference-based (EU, French) system.

Japanese / Korean / Indian / Chinese

Use the JP/IN/CN column in the conversion chart below

These scales use separate integer tables that do not follow a simple formula — always use the chart for accurate conversions.

Australia / New Zealand → UK

Direct equivalence — AU letter = UK letter (same system)

AU M = UK M. No conversion needed. Australia and New Zealand use the identical letter system to the UK.

🧮 International Ring Size Calculator – All Countries (UK 2026)

Enter any ring size or measurement — get instant conversions for all countries

Your Ring Size – All Countries

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💡 Between sizes? Always choose the LARGER size in any country's system

📋 Complete International Ring Size Chart – All Countries (2026)

📋

How to Use This All-Countries Ring Size Chart

Find your known size in any column and read across the row for the equivalent in every other country's system. The Circ.(MM) and Diam.(MM) columns are the universal anchor — any measurement tool in the world produces one of these two numbers. The JP/KR/IN/CN columns show the nearest integer on those number scales. Australian sizes are identical to UK letters. French/Swiss sizes = EU/ISO size minus 40. Starred rows (⭐) are the most common sizes globally.

🇬🇧 UK / 🇦🇺 AU	Diam. (MM)	Circ. (MM)	🇺🇸 US / CA	🇪🇺 EU / ISO	🇫🇷 FR / 🇮🇹 IT / 🇨🇭 CH	🇯🇵 JP / 🇰🇷 KR	🇮🇳 IN	🇨🇳 CN	🇷🇺 RU	Worn By
A	11.9	37.8	—	38	—	1	1	1	12	Child
B	12.3	39.1	—	39	—	2	2	2	12	Child / XS
C	12.7	40.4	1	40	1	3	3	3	13	Child
D	13.1	41.7	2	42	2	4	4	4	13	XS Women
E	13.5	43.0	2.5	43	3	5	5	5	14	XS Women
F	13.9	44.2	3	44	4	6	6	6	14	Petite
G	14.3	45.5	3.5	45	5	7	7	7	14	Small
H	14.7	46.8	4	47	7	8	8	8	15	Small
I	15.1	47.4	4.25	47	7	9	9	9	15	Petite
J	15.5	48.7	4.625	49	9	10	10	10	16	Women
K	15.9	50.0	5.125	50	10	11	11	11	16	Women
L ⭐	16.3	51.2	5.5	51	11	11	11	12	16	Women Popular
M ⭐	16.7	52.5	6	53	13	12	12	12	17	Most Common ♀ ⭐
N ⭐	17.1	53.8	6.5	54	14	13	13	13	17	Women Popular
O	17.5	55.1	7	55	15	14	14	14	18	Unisex
P	17.9	56.3	7.5	56	16	15	15	15	18	Unisex
Q	18.2	57.2	8	58	18	16	16	16	18	Slim Men
R	18.6	58.9	8.625	59	19	17	17	17	19	Men
S	19.1	60.2	9.125	60	20	18	18	18	19	Men
T ⭐	19.5	61.4	9.625	61	21	20	20	20	20	Most Common ♂ ⭐
U ⭐	20.0	62.7	10.25	63	23	21	21	21	20	Men Popular
V ⭐	20.3	64.0	10.625	64	24	22	22	22	20	Men Popular
W	20.7	65.3	11.125	65	25	23	23	23	21	Men
X	21.1	66.6	11.625	66	26	24	24	24	21	Large Men
Y	21.5	67.8	12	68	28	25	25	25	22	Large Men
Z	21.8	68.5	12	69	29	26	26	26	22	XL Men
Z+1	22.2	69.7	12.5	70	30	27	27	27	22	XL / Custom
Z+2	22.6	71.0	13	72	32	29	29	29	23	XXL / Custom

🇦🇺 AU = 🇬🇧 UK — identical letter system, no conversion needed

🇫🇷 FR / 🇮🇹 IT / 🇨🇭 CH = EU size − 40

🇷🇺 RU = inner diameter in mm (round to nearest whole number)

⭐ Starred = most popular sizes worldwide

⬆️ Between sizes? Always go LARGER in any system

🇬🇧 Need the Full UK-Only Chart? Read the Complete UK Ring Size Guide

For a deeper UK-focused guide including 5 measuring methods, step-by-step instructions, metal resizing costs, and expert tips: → Complete Ring Size Guide – UK 2026 | → Ring Size Guide Before Buying a Ring – UK 2026 | → Beginner's Ring Size Guide – UK 2026

💡 International Ring Size Tips – All Countries 2026

🛒 Always check which sizing system a retailer uses before ordering internationally. A US Etsy seller listing rings in "size 6" means US 6 = UK M. A Japanese brand listing "size 12" means JP 12 = UK M. A European brand listing "53" means EU 53 = UK M. Never assume the number matches your home system.
📐 The most reliable international conversion is always to measure in mm first. Measure your inner circumference in mm at home (paper method) or inner diameter in mm (ruler on existing ring). Convert to the target country's system using this chart. Bypasses all ambiguity between national scales.
🇯🇵 Japanese, Korean, Indian, and Chinese ring sizes are integer-based but are not always identical. JP and KR are generally equivalent. Indian and Chinese scales may differ slightly from JP at the extremes. For sizes above JP 22, always verify the exact mm measurement with the retailer rather than relying on the integer number alone.
🇫🇷 French, Italian, Swiss, and Spanish sizing uses a simple formula. Add 40 to convert to EU/ISO (circumference in mm). So French size 13 = 13 + 40 = 53mm = UK M. To go the other way, subtract 40 from your EU/ISO size. This formula works precisely for France, Italy, Switzerland, Spain, Portugal, and most of South America.
🇷🇺 Russian ring sizes are simply the inner diameter in mm rounded to the nearest whole number. If you know your UK size, look up the Diam.(MM) column in the chart above and round to the nearest integer — that is your Russian size. UK M = 16.7mm → Russian 17.
🌍 When buying from any international retailer, always ask for the diameter or circumference in mm. These two measurements are universally unambiguous — every sizing system in the world can be derived from them. If a retailer cannot provide at least one of these measurements, ask for a refund guarantee or do not purchase.
⬆️ The "size up when in doubt" rule applies in every country's sizing system. Whether you are converting UK to US, EU to Japanese, or Indian to Swiss, if your measurement falls between two values in the conversion chart, always choose the larger size in the target system. Resizing down is always cheaper and easier than resizing up — in any country.

🔗 Related Ring Size Guides – International Reference

📚 More Ring Size Guides on This Site

💍 Complete Ring Size Guide – UK 2026 🛍️ Ring Size Guide Before Buying a Ring 📖 Beginner's Ring Size Guide – UK 2026 🎁 Ring Size Guide for Gifts – UK 2026 📊 Average Ring Size UK – Women & Men

🌐 Trusted International Jeweller Resources

🇬🇧 H.Samuel – UK Ring Size Guide 🇬🇧 Beaverbrooks – Ring Size Guide 🇬🇧 Ernest Jones – Size Conversion 🇬🇧 Goldsmiths – Measure Your Ring Size

❓ Ring Size Guide for All Countries – FAQ 2026

What is UK ring size M in US, EU, Japanese, and Indian sizes? ▾

UK M (the most common women's ring size) converts as follows: US 6, EU / ISO 53, French / Italian / Swiss 13, Japanese / Korean 12, Indian 12, Chinese 12, Russian 17, Australian M (identical to UK). Inner diameter: 16.7mm. Inner circumference: 52.5mm.

What is UK ring size T in US, EU, Japanese, and Indian sizes? ▾

UK T (the most common men's ring size) converts as follows: US 9.625, EU / ISO 61, French / Italian / Swiss 21, Japanese / Korean 20, Indian 20, Chinese 20, Russian 20, Australian T (identical to UK). Inner diameter: 19.5mm. Inner circumference: 61.4mm.

Are UK and Australian ring sizes the same? ▾

Yes — UK and Australian ring sizes are identical. Both use the same alphabetical letter system from A to Z+2 with the same millimetre measurements at each size. UK M = Australian M with no conversion needed. The same is true for New Zealand. You can order from any UK or Australian retailer using the same size letter with complete confidence.

How do I convert EU ring size to UK? ▾

The EU / ISO system uses the inner circumference in mm as the size number. To convert: find your EU number in the Circ.(MM) column of the chart above and read the UK letter in the first column. Key conversions: EU 49 = UK J, EU 51 = UK L, EU 53 = UK M, EU 54 = UK N, EU 61 = UK T, EU 63 = UK U. If the EU number falls between two rows, choose the larger UK letter.

How do I convert French, Italian, or Swiss ring size to UK? ▾

Add 40 to the French / Italian / Swiss size number to get the inner circumference in mm (the EU/ISO equivalent). Then find that number in the Circ.(MM) column to get your UK letter. Example: French/Italian size 13 → 13 + 40 = 53mm → UK M. French size 21 → 21 + 40 = 61mm → UK T.

How do I convert Japanese ring size to UK? ▾

Use the JP/KR column in the international conversion chart above. Find your Japanese size number in that column and read the UK letter in the first column. Key conversions: JP 10 = UK K, JP 12 = UK M, JP 13 = UK N, JP 20 = UK T, JP 21 = UK U. Note that Japanese sizes do not follow a simple formula relative to UK — always use the chart rather than trying to calculate directly.

How do I convert US ring size to UK? ▾

Use the US/CA column in the chart above. Key conversions: US 5 = UK K, US 5.5 = UK L, US 6 = UK M, US 6.5 = UK N, US 7 = UK O, US 7.5 = UK P, US 9.625 = UK T, US 10.25 = UK U. The US system uses decimal numbers including half-sizes. Note that some US retailers may round half-sizes differently, so always confirm with the specific retailer's size guide if available.

What is the safest way to order a ring from an international retailer? ▾

The safest approach is: (1) Measure your inner circumference in mm at home using the paper method. (2) Convert to the retailer's sizing system using the chart above. (3) Contact the retailer and ask them to confirm the mm circumference or diameter for your selected size — reputable retailers will always provide this. (4) Check the return and exchange policy before purchasing. (5) If between two sizes, order the larger. For purchases over £150 or for non-resizable ring types, get a free in-store sizing from a UK jeweller first.

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