Should I average two different measurements?

Not automatically. First check whether the finger, hand, tool, conditions, or intended band changed. Preserve the difference and ask for a physical fit check.

Can I copy the size from the matching finger on my other hand?

No. Measure the exact finger and hand where the ring will be worn.

Is one fixed size increase correct for every wide band?

No. Band width and inside profile affect fit differently. Use a gauge or sample that resembles the intended band and have a jeweler confirm it.

Small details protect the fit decision

Avoid the sizing shortcuts that make a clear number less useful.

A measurement needs its finger, hand, unit, method, and band context. Keeping those details together is more reliable than relying on a remembered size alone.

Use the ring size calculator Start with careful fit notes

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

Fit, wear & care—considered together

A clearer decision, with the important context kept beside it

Most sizing errors come from losing one piece of context: the finger, hand, method, unit, ring edge, width, or ordinary fit range.

Use this page when

You are about to trust a home result.
Two methods disagree and you want to find the cause.

Pause this route when

You need urgent help removing a ring.
You want a checklist to override an obvious failed calibration or damaged source ring.

Where this choice often matters

Double-checking an online ring order.
Cleaning up fit notes before a custom design review.

Compare the details

Find the error before choosing a size

Each repair should open the exact tool or guide, not a generic Atelier welcome screen.

Mistake	What it changes	Visible check	Repair
Wrong finger or hand	Personal size context	Label both	Measure intended finger
Outside ring edge	Overstates diameter	Show inner edge	Measure empty interior
Unknown unit/type	Confuses diameter and circumference	Keep label	Return to conversion guide
Ignored width or knuckle	Changes worn fit	Record both	Use comparable gauge

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: Most sizing errors come from losing one piece of context: the finger, hand, method, unit, ring edge, width, or ordinary fit range. Use them to compare what belongs together; make and keep your editable choices in the working path that follows.

What might have changed the result?

Keep every direction that fits.

Finger or handConfirm both.
Inside versus outside edgeUse the empty interior.
Unit or measurement typeLabel mm and diameter/circumference.
Print or screen scalePass physical calibration.
Band widthUse comparable contact width.

Which repair fits?

Choose one direction.

Re-enter a valid measurementKeep method and units.
Measure an existing ringCheck identity and roundness.
Reprint and calibrateStop after any scale failure.
Use physical gaugesChoose for higher confidence.

Questions worth asking

Open the concern that sounds like yours

Each answer stays within this page’s promise—Most sizing errors come from losing one piece of context: the finger, hand, method, unit, ring edge, width, or ordinary fit range.—without making the next step feel heavier than it needs to be.

My two readings differ. Did I fail?

No. The difference is useful evidence; check the method, unit, tension, and ordinary timing.

Can I just average them?

Only after you understand why they differ. An average can hide a wrong measurement type.

What is the quickest reliable check?

Confirm the intended finger, use a known method, repeat it, and keep band width with the result.

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: Most sizing errors come from losing one piece of context: the finger, hand, method, unit, ring edge, width, or ordinary fit range.

Corrected measurement and original errorNeeded before the direction is complete
Width or stackA useful next question
Hand, finger, method, unit, repeat readings, and confidenceKeep 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 “Avoid the sizing shortcuts that make a clear number less useful.”

A visual map of this brief

See what stays known—and what remains open

This route begins with “Protect the measurement by keeping its method, unit, and design context.” 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.