Why do two charts give different converted sizes?

They may use different source dimensions, increments, rounding, half-size conventions, or revisions. Compare the measured inside dimension and identify each chart version.

Is the same number equal in every country?

No. Numeric and letter labels depend on the named system or seller. Never convert an isolated label without identifying its source.

Keep the original size beside the result

Translate a regional ring size without losing its source.

Convert the size you were given, then save the original system and value too. That small detail gives Leyloon a clearer fit record to review.

Use this converted size Save size in profile

Illustrative sizing workbench. Keep the original measurement and system visible when converting; a nominal size alone does not explain fit.

International size converter

Compare a ring size across four common systems.

Choose the system printed on the size you already have. Conversion charts can differ, so treat this as a starting comparison.

Starting systemStarting size

Country labels are not a fit guarantee. Confirm the maker’s chart, intended finger, and band width before choosing a final size.

Starting conversionChoose a starting sizeChoose the system and size you already know. Its physical row and closest listed comparisons will appear here.

Fit, wear & care—considered together

A clearer decision, with the important context kept beside it

Choose the system printed on your known size and see governed nearby equivalents without losing the original label.

Use this page when

A ring, receipt, or jeweler record names a size system.
You are shopping across countries and want physical dimensions beside the labels.

Pause this route when

The number has no system or maker attached.
You expect a sparse chart match to guarantee the fit of a different band.

Where this choice often matters

Ordering a ring from a country that uses another size label.
Sharing a known size with Leyloon while keeping its original system.

Compare the details

Every conversion needs an original and a physical anchor

The production table must cover approved fractional ranges and be reconciled against the current standard.

Field	Example	Why keep it	If missing
Original system	US / UK / EU / JP	Prevents label confusion	Do not convert
Original size	Exact whole or fraction	Preserves source	Ask for the record
Physical dimensions	Diameter and circumference	Shows nearby table rows	Treat match as approximate
Maker and band	Brand chart and width	Explains deviations	Confirm before ordering

Ring-size reference chart

Compare named sizes with inside measurements

Keep your original system and maker’s chart. This table is a comparison aid, not a universal fit promise.

Diameter inner edge to inner edge through the centerCircumference the complete inside path around the ringFit review intended finger, hand, band width, stack, and knuckle

US & Canada	UK, Europe & Australia	Asia	Inside diameter	Inside circumference
3	F	4	14.1 mm	44.3 mm
3.5	G	—	14.5 mm	45.6 mm
4	H	7	14.9 mm	46.8 mm
4.5	I	8	15.3 mm	48.1 mm
5	J	9	15.7 mm	49.3 mm
5.5	K	10	16.1 mm	50.6 mm
6	L	11	16.5 mm	51.8 mm
6.5	M	13	16.9 mm	53.1 mm
7	N	14	17.3 mm	54.3 mm
7.5	O	15	17.7 mm	55.6 mm
8	P	16	18.1 mm	56.9 mm
8.5	Q	17	18.5 mm	58.1 mm
9	R	18	19.0 mm	59.7 mm
9.5	S	19	19.4 mm	60.9 mm
10	T	20	19.8 mm	62.2 mm
10.5	U	22	20.2 mm	63.5 mm
11	V	23	20.6 mm	64.7 mm
11.5	W	24	21.0 mm	66.0 mm
12	X	25	21.4 mm	67.2 mm
12.5	Y	26	21.8 mm	68.5 mm
13	Z.5	27	22.2 mm	69.7 mm
13.5	Z1	—	22.6 mm	71.0 mm

Reviewed 2026-08-25. Source reference: GIA ring-size guide. This table follows GIA’s US and Canada, UK/Europe/Australia, and Asia columns; blank cells are not listed by GIA. Leyloon uses the nearest physical row without interpolation and keeps your original measurement beside it.

Keep your direction organised

The complete choice groups for this decision

These groups support this page’s promise: Choose the system printed on your known size and see governed nearby equivalents without losing the original label. Use them to compare what belongs together; make and keep your editable choices in the working path that follows.

Which system is printed?

Choose one direction.

US / CanadaNumeric whole and fractional sizes.
UK / AustraliaLetter and fractional labels.
EUKeep the exact printed convention.
JapanNumeric system with original chart context.
Maker-specific or otherUse physical measurements where available.

What should the result include?

Keep every direction that fits.

Inside diameterMillimeters across the interior.
Inside circumferenceMillimeters around the interior.
Nearby rowsShows rounding honestly.
Original sourceMaker or document remains attached.

Questions worth asking

Open the concern that sounds like yours

Each answer stays within this page’s promise—Choose the system printed on your known size and see governed nearby equivalents without losing the original label.—without making the next step feel heavier than it needs to be.

Why is my UK letter different on another chart?

Tables and rounding can differ. Keep the original label and compare the physical measurement rather than hiding the mismatch.

Is EU size just circumference?

The selected governed table should state its convention; preserve the original system rather than assuming every numeric label means the same thing.

Can I use the converted result in Atelier?

Yes, with the original system, size, table match, and uncertainty kept together.

Ready when you are

Carry this direction into your design

Leyloon can keep these choices together while you continue. Every detail stays editable. For this page, that means: Choose the system printed on your known size and see governed nearby equivalents without losing the original label.

Original system, size, and governed equivalentsNeeded before the direction is complete
Band width and maker chartA useful next question
Physical measurement and any mismatchKeep it open if you are still deciding

Illustrative ring-wear context across three anatomically complete hands — Illustrative ring-wear context—not a size, width, or knuckle-fit comparison. Use the governed measurements and the exact planned ring construction together. Here it supports the decisions behind “Translate a regional ring size without losing its source.”

A visual map of this brief

See what stays known—and what remains open

This route begins with “Convert the label, but never discard the original size system.” The next choices stay grouped, editable, and connected to that same Atelier brief.

Ring you are sizingChoose the ring context so the measurement stays attached to the right width, profile, and finger.
What measurement do you have?Keep the method with the number. The working tool above can help compare it without replacing the maker's final fit check.
Band width or stackChoose the planned contact width. Exact millimeters stay editable.
What could change the fit?Choose the closest context. You can add the exact measurements privately in Atelier.

Start with what matters on this page

Keep the measurement with the ring it belongs to

Choose how you measured and the ring context. The number stays private, and Atelier carries the method, width, and fit notes together.

01 Ring you are sizing

Choose the ring context so the measurement stays attached to the right width, profile, and finger.

02 What measurement do you have?

Keep the method with the number. The working tool above can help compare it without replacing the maker's final fit check.

03 Band width or stack

Choose the planned contact width. Exact millimeters stay editable.

04 What could change the fit?

Choose the closest context. You can add the exact measurements privately in Atelier.

What else should Atelier help with?

Add only the parts you want to explore. The page topic is already included.

Fit and formIncluded from this page

Nothing selected yet. You can still continue and answer in Atelier.

Published customer proof

Real experiences, kept separate from promises

Only approved purchase-linked reviews appear here. An illustrative scene is never presented as a customer, and one person’s experience is never treated as a promise for another piece.

See what Leyloon customers have shared

Read recent shop reviews on Etsy, then come back when you are ready to shape your own fit and jewelry direction.

See Leyloon reviews on Etsy

These reviews reflect individual Leyloon service experiences. Your fit and jewelry direction and quote request are reviewed on their own.