Keep the measurement useful

Turn one careful measurement into a ring-size direction.

Use the calculator as a starting point, then keep the finger, hand, unit, and band width with the result. Leyloon can review those details with the design you choose.

Use this size in a ring design Save to your profile

Educational diagram—not physical scale or a personal-size promise. A nearest row is a comparison, not an interpolated or guaranteed fit result.

Ring size starting point

Turn one careful measurement into a US size direction.

Measure more than once at a comfortable temperature. The result is a starting US direction, not a guaranteed fit.

What did you measure?Inside diametermm

Home measurements, finger shape, temperature, and band width can change the fit. Ask Leyloon or a local jeweler to review the intended finger and band before ordering.

Nearest chart rowAdd a measurementEnter 14.1–22.6 mm to compare the common chart range.

Fit, wear & care—considered together

A clearer decision, with the important context kept beside it

Enter an inside diameter or finger circumference and keep the original measurement beside a Leyloon size table comparison.

Use this page when

You measured millimeters carefully and know which measurement type you used.
You want a starting comparison before reviewing band width and knuckle fit.

Pause and choose another path when

The ring you measured is oval, bent, or worn on another finger.
You only know height, weight, or an unlabeled number.

Where this choice often matters

Turning an existing-ring diameter into a ring-size direction.
Checking a home finger measurement before beginning a custom ring.

Compare the details

A result should show its physical basis

The calculator preserves your original measurement, compares it with 22 US half-size rows from 3 through 13.5, and shows nearby rows instead of inventing an in-between size.

Input	Example display	Calculation role	Still review
Inside diameter	17.3 mm	Match to Leyloon size table	Roundness and inner edge
Finger circumference	54.4 mm	Match to nearest table values	Measurement tension and knuckle
Named size	US 7	Show physical dimensions	Source system and maker
Between rows	Two nearby sizes	Show both, never hide rounding	Band width and wearer trial

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.

Questions worth asking

Open the concern that sounds like yours

Choose the question that sounds like yours. Each answer keeps the next step clear without closing decisions that still need review.

Why not give one exact size?

The table can match a measurement, but personal fit still depends on how it was taken and on the exact ring.

What if my result sits between sizes?

Keep both nearby rows and compare them with the intended width, knuckle, and fit preference.

Can the result go into Atelier?

Yes, once valid, with the original method, value, unit, and starting result still editable.

Ready when you are

Carry this direction into your design

Leyloon can keep these choices together while you continue. Every detail stays editable. Your choices stay editable as you continue.

Original type, value, unit, and Leyloon size table resultNeeded before the direction is complete
Exact or planned band widthA useful next question
Interior profile if knownKeep it open if you are still deciding
Intended hand, finger, knuckle, and confidenceKeep it open if you are still deciding

Start with what matters on this page

Keep the measurement and the ring context together

The calculator compares a millimeter reading with a reference chart. Choose what you measured, then keep the fit details Leyloon should review beside the result.

01 What did you measure in the calculator?Choose one

Keep the measurement type beside the raw millimeter value. A converted row is a comparison, not a personal fit promise.

02 What should stay beside the result?

Keep every detail that may change how the finished ring feels. These notes remain private and editable.

03 Ring you are sizing

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

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

Choose what did you measure in the calculator? to continue. “Not sure” is a valid choice.

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.