International Ring Size Chart UK – Complete Conversion Guide 2026

International Ring Size Chart – UK Conversion Guide 2026

The complete international ring size chart — convert UK sizes to US, EU, France, Germany, Japan, India, Switzerland, Italy, Spain, Australia & more. Updated 2026 with full mm diameter & circumference reference

🇬🇧 UK A – Z+6 🇺🇸 US / Canada 🇪🇺 EU / ISO 🇯🇵 Japan 🇮🇳 India 🇨🇭 Switzerland 🇮🇹 Italy / Spain 🇦🇺 Australia

10+

🌍 Countries
Covered

📐 Universal
Reference Unit

A–Z+6

🇬🇧 Full UK
Size Range

±½

⚠️ Always Allow
Half Size Tolerance

ℹ️

International Ring Size Chart – How It Works

Every country uses a different ring sizing system. The UK uses letters (A–Z+6), the US uses numbers (0–16), and Europe uses circumference in mm (e.g. 49, 50). The only universal reference is the inner diameter or circumference in millimetres. When converting between international ring size systems, always use the diameter in mm as your anchor point — never convert letter to number directly without checking the mm value first.

🌐 How Each International Ring Size System Works

🇬🇧

United Kingdom

Letters A – Z+6

Uses alphabet letters with half sizes (e.g. M, M½). Most common women's: M. Most common men's: T.

🇺🇸

USA & Canada

Numbers 0 – 16

Uses decimal numbers with quarter sizes (e.g. 6, 6¼). Most common women's: 6–7. Most common men's: 9–10.

🇪🇺

Europe (EU/ISO)

Circumference in mm (41–76)

Uses inner circumference in mm as the size (e.g. 49, 52). Same system used in France, Germany & most of EU.

🇯🇵

Japan & China

Numbers 1 – 30

Uses whole numbers based on inner circumference. Japan size 11 ≈ UK M. Japan size 20 ≈ UK T.

🇮🇳

India

Numbers 1 – 30

Similar to the Japanese system. India size 10 ≈ UK M. India size 19 ≈ UK T.

🇨🇭

Switzerland

Diameter in mm (–1.5)

Swiss size = inner diameter in mm minus 1.5 (e.g. diameter 15.9 mm = Swiss size 14.4). Often used by luxury watch brands.

🇮🇹

Italy & Spain

Numbers (EU – 40)

Italian size = EU/ISO circumference mm minus 40 (e.g. EU 49 = Italian size 9). Spain uses the same system.

🇦🇺

Australia & NZ

Letters A – Z+6

Same letter system as the UK — direct conversion. Australian sizes are identical to UK sizes.

🇩🇪

Germany

Diameter in mm

Germany uses the inner diameter in mm directly as the ring size (e.g. 16 mm, 17 mm). Simple and precise.

🧮 International Ring Size Converter Calculator

Enter your measurement to find your international ring size across all systems

Your International Ring Sizes

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👩 International Ring Size Chart – Women's Sizes (UK F – P)

🇬🇧 UK	Diam. (mm)	Circ. (mm)	🇺🇸 US	🇪🇺 EU	🇯🇵 Japan	🇮🇳 India	🇨🇭 Swiss	🇮🇹 Italy
F	13.5	42.6	3	43	4	3	12.0	3
G	13.9	43.6	3.5	44	5	4	12.4	4
H	14.2	44.8	4	45	6	5	12.7	5
I	14.5	45.7	4.25	46	7	6	13.0	6
J	14.9	46.8	4.75	47	8	7	13.4	7
K	15.2	47.8	5.25	48	9	8	13.7	8
L	15.5	48.7	5.75	49	10	9	14.0	9
M ⭐	15.9	49.9	6	50	11	10	14.4	10
N ⭐	16.2	50.9	6.5	51	12	11	14.7	11
O	16.5	51.9	7	52	13	12	15.0	12
P	16.9	53.0	7.5	53	14	13	15.4	13

⭐ UK M = US 6 = EU 50 = Japan 11 = India 10

⭐ UK N = US 6.5 = EU 51 = Japan 12 = India 11

👨 International Ring Size Chart – Men's Sizes (UK P – Z+2)

🇬🇧 UK	Diam. (mm)	Circ. (mm)	🇺🇸 US	🇪🇺 EU	🇯🇵 Japan	🇮🇳 India	🇨🇭 Swiss	🇮🇹 Italy
P	16.9	53.0	7.5	53	14	13	15.4	13
Q	17.2	54.1	8	54	15	14	15.7	14
R	17.5	55.1	8.5	55	16	15	16.0	15
S	17.8	56.0	9	56	17	16	16.3	16
T ⭐	19.8	62.1	9.5	60	20	19	18.3	20
U ⭐	19.8	62.1	10	61	21	20	18.3	21
V ⭐	20.2	63.4	10.5	62	22	21	18.7	22
W	20.6	64.6	11	63	23	22	19.1	23
X	21.0	65.9	11.5	65	24	23	19.5	25
Y	21.4	67.2	12	66	25	24	19.9	26
Z	21.9	68.5	12.5	68	26	25	20.4	28
Z+1	22.2	69.7	13	69	27	26	20.7	29
Z+2	22.5	70.7	13.5	70	28	27	21.0	30

⭐ UK T = US 9.5 = EU 60 = Japan 20 = India 19

⭐ UK V = US 10.5 = EU 62 = Japan 22 = India 21

🇦🇺 Australia = same as UK sizes

📊 Full International Ring Size Chart A – Z+6 with mm Reference

🇬🇧 UK	Diam. (mm)	Circ. (mm)	🇺🇸 US	🇪🇺 EU	🇯🇵 Japan	🇮🇳 India	🇩🇪 Germany
A	11.9	37.4	—	37	—	—	11.9 mm
C	12.5	39.1	—	39	—	—	12.5 mm
E	13.2	41.5	2	42	3	2	13.2 mm
F	13.5	42.6	3	43	4	3	13.5 mm
G	13.9	43.6	3.5	44	5	4	13.9 mm
H	14.2	44.8	4	45	6	5	14.2 mm
I	14.5	45.7	4.25	46	7	6	14.5 mm
J	14.9	46.8	4.75	47	8	7	14.9 mm
K	15.2	47.8	5.25	48	9	8	15.2 mm
L	15.5	48.7	5.75	49	10	9	15.5 mm
M ⭐	15.9	49.9	6	50	11	10	15.9 mm
N	16.2	50.9	6.5	51	12	11	16.2 mm
O	16.5	51.9	7	52	13	12	16.5 mm
P	16.9	53.0	7.5	53	14	13	16.9 mm
Q	17.2	54.1	8	54	15	14	17.2 mm
R	17.5	55.1	8.5	55	16	15	17.5 mm
S	17.8	56.0	9	56	17	16	17.8 mm
T ⭐	19.8	62.1	9.5	60	20	19	19.8 mm
U ⭐	19.8	62.1	10	61	21	20	19.8 mm
V	20.2	63.4	10.5	62	22	21	20.2 mm
W	20.6	64.6	11	63	23	22	20.6 mm
X	21.0	65.9	11.5	65	24	23	21.0 mm
Y	21.4	67.2	12	66	25	24	21.4 mm
Z	21.9	68.5	12.5	68	26	25	21.9 mm
Z+1	22.2	69.7	13	69	27	26	22.2 mm
Z+2	22.5	70.7	13.5	70	28	27	22.5 mm

👁️ Visual International Ring Size Reference

Most Popular International Sizes — Women's

UK M (EU 50 / US 6 / Japan 11) is the most commonly purchased women's ring size internationally.

UK J

US 4.75 · EU 47

UK L

US 5.75 · EU 49

UK M ⭐

US 6 · EU 50

UK N

US 6.5 · EU 51

UK O

US 7 · EU 52

Most Popular International Sizes — Men's

UK T (EU 60 / US 9.5 / Japan 20) is the most commonly purchased men's ring size internationally.

UK S

US 9 · EU 56

UK T ⭐

US 9.5 · EU 60

UK U

US 10 · EU 61

UK V

US 10.5 · EU 62

UK W

US 11 · EU 63

📏 How to Use the International Ring Size Chart

3 Steps to Convert Any Ring Size Internationally

Always start with the diameter in mm

The diameter in mm is the only truly universal measurement across all international ring size systems. Measure the inner diameter of an existing ring with a ruler, or measure your finger circumference and divide by π (3.14159) to get the diameter.

Find your diameter in the chart

Locate your diameter value in the Diam. (mm) column. Read across the row to find your size in every system simultaneously — UK, US, EU, Japan, India, Germany, Switzerland and Italy.

Allow ½ size tolerance when ordering abroad

International ring size charts are approximations. Minor manufacturing differences between countries mean you should always allow ±½ size tolerance when ordering a ring sized using a foreign system. If possible, order from a retailer that offers free resizing.

📐 International Conversion Formulas

UK → EU / ISO Size

EU Size = Inner Circumference in mm (rounded to nearest whole)

Example: UK M = 49.9 mm circumference → EU Size 50

UK → Swiss Size

Swiss Size = Diameter (mm) − 1.5

Example: UK M = 15.9 mm diameter → Swiss Size 14.4

UK → Italian / Spanish Size

Italian Size = EU Size − 40

Example: UK M = EU 50 → Italian Size 10

Diameter → Circumference (Universal)

Circumference (mm) = Diameter (mm) × π (3.14159)

Example: 15.9 mm × 3.14159 = 49.9 mm → UK M / EU 50 / US 6

💡 Expert Tips for Using an International Ring Size Chart

📐mm diameter is the universal anchor — when converting between international ring size systems, always verify using the mm diameter. Never convert letter to number directly without checking the mm value, as rounding errors accumulate.
🇦🇺Australia & New Zealand = UK sizes — if you are ordering from an Australian or New Zealand jeweller, their ring sizes are identical to UK sizes. No conversion needed at all.
🇺🇸US quarter sizes matter — US ring sizes come in quarter increments (e.g. 6, 6¼, 6½, 6¾). When converting from UK to US, the nearest quarter size to your mm value gives the best fit rather than rounding to a half size.
🇯🇵Japanese sizes run small — Japan and China use whole number sizes that are closely tied to circumference in mm minus a constant. Always verify the mm diameter when ordering from Japanese retailers, as their size chart starts at a smaller base than Western systems.
🛍️Online international orders — when ordering a ring from an overseas retailer (e.g. Etsy US sellers, European jewellers), always ask for the inner diameter in mm before ordering. Most reputable sellers will provide this on request.
🔁Allow for resizing — international sizing inconsistencies are common. Always choose retailers offering free or low-cost international resizing, or order ½ size up if in doubt — it is easier to size a ring down than up.
💒Wedding rings: get sized in person — for wedding bands purchased internationally (e.g. from a US or Italian designer), always get sized in person at a local UK jeweller first and provide the mm diameter to the overseas retailer for the most accurate international fit.

🌍 International Ring Size Chart – Key Equivalents at a Glance (2026)

UK M = US 6 = EU 50 = Japan 11 = India 10 = Swiss 14.4 = Italian 10 = German 15.9 mm · UK T = US 9.5 = EU 60 = Japan 20 = India 19 = Swiss 18.3 = Italian 20 = German 19.8 mm · Australia / NZ uses identical UK letter sizes · Always verify with diameter in mm before ordering internationally.

📚 Related UK Ring Size Guides

For UK-specific sizing, visit our full Finger Ring Size Chart UK covering every size A to Z+6 with diameter and circumference data. See our Women's Ring Size Chart UK for sizes F–P, or the Average Men's Ring Size UK guide for sizes P–Z+6. For international jewellery standards, the ISO 8653 standard is the official international reference for ring size definitions used by jewellers worldwide.

❓ International Ring Size Chart – FAQs 2026

How do I convert UK ring sizes to US using an international ring size chart? ▾

To convert UK to US ring sizes, find your UK letter size in the international ring size chart above and read across to the US column. Key conversions: UK M = US 6, UK N = US 6.5, UK T = US 9.5, UK V = US 10.5. Always verify using the diameter in mm to ensure accuracy, as slight differences exist between manufacturers.

What is EU ring size 54 in UK? ▾

EU ring size 54 corresponds to approximately UK Size Q (diameter 17.2 mm, circumference 54.1 mm). The EU system uses the inner circumference in mm directly as the size number, so EU 54 = 54 mm circumference. This falls in the lower men's / upper unisex range of the UK international ring size chart.

Is Australian ring sizing the same as UK? ▾

Yes — Australian and New Zealand ring sizes are identical to UK ring sizes. Both use the same alphabetical letter system (A–Z+6). If you are ordering a ring from an Australian jeweller, your UK size is directly applicable with no conversion needed.

What is the most reliable way to convert ring sizes internationally? ▾

The most reliable method is to use the inner diameter in millimetres as your reference. Measure the inner diameter of a well-fitting ring (or calculate it from your circumference measurement by dividing by π), then match it to the diameter column in the international ring size chart. This works across every country's sizing system without relying on potentially inconsistent letter-to-number shortcuts.

What is Japan ring size 13 in UK? ▾

Japan ring size 13 corresponds to approximately UK Size O (diameter 16.5 mm, circumference 51.9 mm, US size 7). This is in the upper women's range on the UK international ring size chart. Use the diameter in mm to cross-check when ordering from Japanese jewellery retailers.

How does the Swiss ring sizing system work? ▾

The Swiss ring size system uses the formula: Swiss Size = Inner Diameter (mm) − 1.5. For example, UK Size M has a diameter of 15.9 mm, giving a Swiss size of 14.4. UK Size T (19.8 mm diameter) = Swiss size 18.3. Swiss sizing is commonly used by luxury watch and jewellery brands including those based in Geneva and Zurich.

What is Italian ring size 12 in UK? ▾

Italian ring size 12 = EU size 52 = UK Size O (diameter 16.5 mm, circumference 51.9 mm). The Italian system uses the formula: Italian Size = EU Size − 40. So Italian 12 + 40 = EU 52 = approximately UK O. This is in the women's upper range of the international ring size chart.

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