AU to Japan Ring Size Conversion – Australian to Japanese Ring Size Chart

AU to Japan Ring Size Conversion

Convert Australian ring sizes to Japanese ring sizes instantly — complete AU to Japan chart with diameter in mm, circumference, and reverse Japan to AU lookup

🇦🇺 Australian / UK Letter Sizes 🇯🇵 Japan Numeric Sizes 📏 Sizes A – Z+3 📐 mm Measurements 🔄 Instant Calculator

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Japan Size for
AU Women's Avg (N)

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Japan Size for
AU Men's Avg (T)

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Sizes Covered
A to Z+3

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0–30

Japan Size
Range

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AU ↔ Japan Ring Size Calculator

Select your Australian size OR enter a Japan size to instantly convert

Converted Size

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Complete AU to Japan Ring Size Chart

🇦🇺 AU / UK Size	🇯🇵 Japan Size	Diameter (mm)	Circumference (mm)	🇺🇸 US Size	Typical Wearer
A	0.5	12.0 mm	37.8 mm	½	Child
B	1	12.3 mm	38.5 mm	1	Child
C	2	12.5 mm	39.3 mm	1½	Child
D	3	12.8 mm	40.0 mm	2	Child
E	4	13.0 mm	40.8 mm	2½	Child
F	5	13.2 mm	41.5 mm	3	Child
G	6	13.5 mm	42.3 mm	3½	Small Women
H	8	13.7 mm	43.0 mm	4	Small Women
I	9	13.9 mm	43.8 mm	4½	Women
J	10	14.2 mm	44.5 mm	5	Women
K	11	14.4 mm	45.3 mm	5½	Women
L	12	14.6 mm	46.0 mm	6	Women
M	13	14.9 mm	46.8 mm	6½	Popular ♀
N ⭐	14	15.1 mm	47.5 mm	7	Most Common ♀
O	15	15.3 mm	48.3 mm	7½	Popular ♀
P	16	15.6 mm	49.0 mm	8	Women / Men
Q	17	15.8 mm	49.8 mm	8½	Women / Men
R	18	16.1 mm	50.5 mm	9	Men
S	19	16.3 mm	51.3 mm	9½	Men
T ⭐	20	16.6 mm	52.0 mm	10	Most Common ♂
U	22	16.8 mm	52.8 mm	10½	Popular ♂
V	23	17.0 mm	53.5 mm	11	Men
W	24	17.3 mm	54.3 mm	11½	Men
X	25	17.5 mm	55.0 mm	12	Large Men
Y	26	17.8 mm	55.8 mm	12½	Large Men
Z	27	18.0 mm	56.5 mm	13	Large Men
Z+1	28	18.2 mm	57.3 mm	13½	XL
Z+2	29	18.5 mm	58.0 mm	14	XL
Z+3	30	18.7 mm	58.8 mm	14½	XL

⭐ AU N = Japan 14 — most common women's size

⭐ AU T = Japan 20 — most common men's size

⚠️ Japan skips size 7 — no exact equivalent for some AU half-sizes

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Quick Reference — Most Common Sizes

🇦🇺 AU Size	🇯🇵 Japan Size	Who Wears This	Diameter (mm)	🇺🇸 US Size
L	12	Average women's (smaller hand)	14.6 mm	6
M	13	Popular women's size	14.9 mm	6½
N ⭐	14	Most common Australian women's	15.1 mm	7
O	15	Popular women's size	15.3 mm	7½
P	16	Unisex / larger women's	15.6 mm	8
R	18	Average men's (smaller hand)	16.1 mm	9
S	19	Popular men's size	16.3 mm	9½
T ⭐	20	Most common Australian men's	16.6 mm	10
U	22	Popular men's size	16.8 mm	10½
V	23	Larger men's size	17.0 mm	11

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How to Convert AU to Japan Ring Size

Method 1 — Use the Chart Above (Fastest)

Find your Australian size

Locate your AU letter size (e.g. N) in the left column of the conversion chart above.

Read across to Japan column

The corresponding Japan numeric size is shown in the second column — for AU N, the Japan size is 14.

Verify with diameter or circumference

Cross-check using the diameter (mm) column to confirm you have the correct match before ordering.

Method 2 — Use the Calculator Above

Select conversion direction

Choose "Australian → Japan" or "Japan → Australian" from the dropdown.

Select your size

Pick your known size from the dropdown list provided.

Click Convert

Your converted size is displayed instantly along with the diameter and circumference in mm.

📐 Key Conversion Facts

AU Letter → Japan Number

Each AU letter = one Japan numeric size (e.g. AU N = Japan 14)

Note: Japan skips size 7 — there is no Japan 7 in the standard system. AU G maps to Japan 6, AU H maps to Japan 8.

Japan → AU Letter

Japan 14 → AU N · Japan 20 → AU T · Japan 27 → AU Z

Always verify by matching the diameter (mm) value when converting for an online purchase.

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Understanding Japan Ring Sizes

Japanese ring sizes use a numeric system starting from 0.5 and increasing by 1 for each size step. Unlike the Australian/UK letter system (A, B, C…) or the US fractional system (3, 3½, 4…), Japan uses whole numbers such as 1, 2, 3, 5, 6, 8, 9, 10 and so on. Note that Japan size 7 is traditionally skipped in most Japanese jeweller standards, so AU G (Japan 6) jumps directly to AU H (Japan 8).

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Australian / UK

Letter-based: A, B, C … Z, Z+1, Z+2, Z+3. Standard across Australia, UK, Ireland, New Zealand.

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Japanese

Numeric: 0.5 to 30+. Used across Japan, and common on Japanese jewellery e-commerce platforms.

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US / Canada

Fractional numeric: 3, 3½, 4 … 13, 14. Often seen on international jewellery sites alongside AU sizes.

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EU / ISO

Inner circumference in mm: 44, 46, 47 … Used across Europe, widely listed on EU jewellery brands.

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Diameter (mm)

Universal reference — when in doubt, always confirm using the inner diameter in millimetres.

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No Half-Sizes

Japanese standard sizes are mostly whole numbers. Half-sizes (e.g. Japan 8.5) exist but are less commonly listed.

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Tips for Buying Japanese Rings from Australia

📐Always check the diameter in mm — both the AU and Japan size columns can have minor rounding differences between brands. The inner diameter in mm is the most universal and reliable measurement.
📦Contact the Japanese seller for their own chart — luxury Japanese jewellery brands such as TASAKI, Mikimoto, and NIWAKA may use slightly different size increments. Always request their size guide before purchasing.
☀️Measure your finger at the right time — fingers swell during warm weather and after physical activity. Measure in the afternoon when your fingers are at their natural widest for the best fit.
🔢Note the Japan size 7 skip — Japan traditionally omits size 7. If a chart lists Japan 7, verify it against the diameter column to ensure it matches what you expect for AU G or AU H.
📏If between sizes, size up — when your measurement falls between two Japan sizes, always choose the larger size. It's easier to have a ring resized smaller than larger.
💍Wide band rings need a larger size — rings wider than 6mm tend to fit more snugly. If ordering a wide Japanese ring, go one size up from your standard AU conversion.

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Frequently Asked Questions

What is Australian ring size N in Japan? ▾

Australian ring size N is equivalent to Japan size 14. AU 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 Australia.

What is Australian ring size T in Japan? ▾

Australian ring size T is equivalent to Japan size 20. AU T has an inner diameter of 16.6 mm and a circumference of approximately 52.0 mm. It is the most common men's ring size in Australia.

Why does Japan skip ring size 7? ▾

The Japanese ring sizing standard traditionally omits size 7. This is a historical convention in the Japanese jewellery industry. As a result, AU G maps to Japan 6, and AU H maps directly to Japan 8 — there is no Japan 7 equivalent in most standard charts.

Are Australian and UK ring sizes the same? ▾

Yes. Australian ring sizes use exactly the same letter-based system as UK ring sizes. AU size N is identical to UK size N. This means you can use any UK-to-Japan ring size chart interchangeably with an AU-to-Japan chart.

How do I convert a Japan ring size to Australian? ▾

Use the calculator at the top of this page and select "Japan → Australian" from the direction dropdown. Alternatively, find your Japan size in the chart above and read the corresponding AU letter size in the first column. For example, Japan 14 = AU N, Japan 20 = AU T.

Is Japan size 13 the same as AU M? ▾

Yes. Japan ring size 13 is equivalent to Australian size M. Both correspond to an inner diameter of approximately 14.9 mm and a circumference of 46.8 mm. AU M / Japan 13 is a popular women's size.

Can I use this chart for buying rings from Japan online? ▾

Yes, this chart is specifically designed for Australians shopping on Japanese jewellery websites (such as Rakuten, ZOZOTOWN, or brand sites like TASAKI and Mikimoto). Always confirm the inner diameter in mm with the specific retailer, as premium brands may use slightly adjusted increments.

What if my AU size falls between two Japan sizes? ▾

Always round up to the next Japan size. For example, if your measurement falls between Japan 13 and Japan 14, choose Japan 14. A slightly loose ring is much easier for a jeweller to resize than one that is too small. For wide-band rings (over 6 mm), size up by one full size as a precaution.