AU to UK Ring Size Conversion – Australian to British Ring Size Chart

AU to UK Ring Size Conversion

Australian and UK ring sizes use the exact same letter system — sizes A to Z+3. Complete chart with diameter, circumference and US / EU international equivalents.

🇦🇺 Australian Sizes 🇬🇧 British Sizes 📏 A – Z+3 ✅ Same Standard 🔄 US · EU · Japan · India

✅

Same

AU & UK use
identical sizing

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A–Z+3

Full letter
size range

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Australian and UK Ring Sizes Are Identical — No Conversion Needed

Australia adopted the British ring size standard, so both countries use the exact same letter system from A to Z+3. If you wear a Size N in Australia, you are a Size N in the UK. The chart below confirms every size with its exact diameter and circumference measurements in mm.

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Australian Ring Sizes

Uses letters A to Z+3. Based on inner circumference measured in millimetres. Follows the same physical standard as the UK.

✅ Commonwealth Standard

🇬🇧

UK Ring Sizes

Uses letters A to Z+6. The original British letter system — adopted by Australia, New Zealand and Ireland.

✅ Identical to Australian

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Complete AU / UK Ring Size Chart

AU / UK Size	Diameter (mm)	Circumference (mm)	Diameter (in)	Circumference (in)	Typical Wearer
A	12.0 mm	37.8 mm	0.472″	1.49″	Child
B	12.3 mm	38.5 mm	0.484″	1.52″	Child
C	12.5 mm	39.3 mm	0.492″	1.55″	Child
D	12.8 mm	40.0 mm	0.504″	1.57″	Child
E	13.0 mm	40.8 mm	0.512″	1.61″	Child
F	13.2 mm	41.5 mm	0.520″	1.63″	Child
G	13.5 mm	42.3 mm	0.531″	1.66″	Small Women
H	13.7 mm	43.0 mm	0.539″	1.69″	Small Women
I	13.9 mm	43.8 mm	0.547″	1.72″	Women
J	14.2 mm	44.5 mm	0.559″	1.75″	Women
K	14.4 mm	45.3 mm	0.567″	1.78″	Women
L	14.6 mm	46.0 mm	0.575″	1.81″	Women
M	14.9 mm	46.8 mm	0.587″	1.84″	Popular ♀
N ⭐	15.1 mm	47.5 mm	0.594″	1.87″	Most Common ♀
O	15.3 mm	48.3 mm	0.602″	1.90″	Popular ♀
P	15.6 mm	49.0 mm	0.614″	1.93″	Women / Men
Q	15.8 mm	49.8 mm	0.622″	1.96″	Women / Men
R	16.1 mm	50.5 mm	0.634″	1.99″	Men
S	16.3 mm	51.3 mm	0.642″	2.02″	Men
T ⭐	16.6 mm	52.0 mm	0.654″	2.05″	Most Common ♂
U	16.8 mm	52.8 mm	0.661″	2.08″	Popular ♂
V	17.0 mm	53.5 mm	0.669″	2.11″	Men
W	17.3 mm	54.3 mm	0.681″	2.14″	Men
X	17.5 mm	55.0 mm	0.689″	2.17″	Large Men
Y	17.8 mm	55.8 mm	0.701″	2.20″	Large Men
Z	18.0 mm	56.5 mm	0.709″	2.22″	Large Men
Z+1	18.2 mm	57.3 mm	0.717″	2.26″	XL
Z+2	18.5 mm	58.0 mm	0.728″	2.28″	XL
Z+3	18.7 mm	58.8 mm	0.736″	2.31″	XL

⭐ Size N = Most common women's size (AU & UK)

⭐ Size T = Most common men's size (AU & UK)

✅ AU size = UK size — always identical

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AU / UK to International Size Conversion

🇦🇺🇬🇧 AU / UK	🇺🇸 US / Canada	🇪🇺 EU / ISO	🇯🇵 Japan	🇮🇳 India	Diameter (mm)	Circ. (mm)
A	0.5	38	1	—	12.0 mm	37.8 mm
D	2	40	3	—	12.8 mm	40.0 mm
F	3	41	5	1	13.2 mm	41.5 mm
H	4	43	7	3	13.7 mm	43.0 mm
J	4.75	44	8	5	14.2 mm	44.5 mm
L	5.5	46	10	8	14.6 mm	46.0 mm
M	6	46.5	11	9	14.9 mm	46.8 mm
N ⭐	6.5	47	12	10	15.1 mm	47.5 mm
O	7	48	13	11	15.3 mm	48.3 mm
P	7.5	49	14	12	15.6 mm	49.0 mm
Q	8	49.5	15	13	15.8 mm	49.8 mm
R	8.5	51	16	14	16.1 mm	50.5 mm
S	9	51.5	17	15	16.3 mm	51.3 mm
T ⭐	9.5	52	18	16	16.6 mm	52.0 mm
U	10	53	19	17	16.8 mm	52.8 mm
V	10.5	54	20	18	17.0 mm	53.5 mm
W	11	54.5	21	19	17.3 mm	54.3 mm
X	11.5	55	22	20	17.5 mm	55.0 mm
Z	12.5	57	24	22	18.0 mm	56.5 mm
Z+1	13	58	25	23	18.2 mm	57.3 mm
Z+3	14	60	27	25	18.7 mm	58.8 mm

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AU / UK Ring Size Calculator

Enter your finger measurement to find your AU & UK ring size instantly

Your Australian & UK Ring Size

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Tips for Buying Rings Between AU & UK

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No conversion needed: AU and UK ring sizes are 100% identical — just quote the same letter size to any jeweller in Australia or the UK.
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Measure at end of day: Fingers are slightly larger in the evening due to body heat. Measure then for the most accurate fit.
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Temperature matters: Cold weather shrinks fingers; warm weather expands them. Always size up if you're between two sizes.
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Buying online from UK stores: Since sizes match, simply order your usual AU letter size from any UK jeweller such as Pandora UK, Tiffany London or Argent.
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Wide bands fit tighter: If ordering a wide band ring (over 6mm), consider going half a size up for comfort.
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Converting to US or EU: Use the International Conversion table above to find your US or EU equivalent if shopping from American or European stores.

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Sizing Formulas

📐 Conversion Formulas

Diameter → Circumference

Circumference (mm) = Diameter (mm) × 3.14159

Example: 15.1 mm × 3.14159 = 47.4 mm → AU / UK Size N

Inches → Millimetres

mm = inches × 25.4

Example: 0.594″ × 25.4 = 15.1 mm → AU / UK Size N

AU / UK → US Approximate

US Size ≈ (AU Letter Position − 1) ÷ 2

Example: AU Size N = 13th letter → (13−1)÷2 = 6 → US Size 6.5 (approx)

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Frequently Asked Questions

Are Australian and UK ring sizes the same? ▼

Yes — Australian ring sizes are identical to UK ring sizes. Both countries use the same letter system from A to Z+3, based on the same inner circumference measurements in millimetres. No conversion is needed when shopping between the two countries.

What is AU Size N in UK? ▼

AU Size N is exactly UK Size N — they are the same size. Size N has an inner diameter of 15.1 mm and a circumference of approximately 47.5 mm. It is the most common women's ring size in both Australia and the UK.

What is AU Size T in UK? ▼

AU Size T is exactly UK Size T. It has an inner diameter of 16.6 mm and a circumference of 52.0 mm. Size T is the most common men's ring size in both Australia and the UK.

How do I convert my AU ring size to US? ▼

Use the International Conversion table on this page. For example, AU/UK Size N = US Size 6.5, AU/UK Size T = US Size 9.5. US sizes use a numerical scale, so the letter-to-number match requires a lookup table rather than a direct formula.

How do I convert my AU ring size to EU? ▼

EU ring sizes are based directly on the inner circumference in mm. For example, AU/UK Size N (47.5 mm circumference) = EU Size 47. Use the International Conversion table above for all sizes. EU sizes are used across most of continental Europe.

Can I order from a UK jeweller using my Australian ring size? ▼

Yes, absolutely. Since AU and UK sizes are identical, simply provide your Australian letter size to any UK jeweller — online or in-store — and it will be correct. Brands like Pandora, Tiffany, and independent UK jewellers all use the same letter system.

What if I am between two ring sizes? ▼

If your measurement falls between two sizes, always choose the larger size. This is especially important for wide-band rings (over 6mm), which fit more snugly than thin bands. For comfort, it is easier to resize a ring down than to stretch one up.

Do New Zealand and Ireland also use the same ring sizes? ▼

Yes. New Zealand and Ireland also use the British letter ring size standard, the same as Australia and the UK. So an AU Size N = UK Size N = NZ Size N = Irish Size N.