Ring Size Chart & Measurement Checker

Measure a ring or your finger. Check repeat readings before choosing a reference size.

Published reference

International ring size chart

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Column names follow the Brilliant Earth chart; they are not a universal standard. A dash means the source leaves that conversion unavailable.

Inside circumference	US / Canada / Mexico	UK / Australia / Ireland / NZ / South Africa	France	Germany / Russia / Ukraine / Asia	India / China / Japan / South America / Turkey / Israel	Italy / Spain / Netherlands / Switzerland
44.2 mm	US 3	F	44	14	4	4
44.8 mm	US 3.25	F 1/2	45	14 1/4	—	4 5/8
45.5 mm	US 3.5	G	45.5	14 1/2	5	5 1/4
46.1 mm	US 3.75	G 1/2	46	14 3/4	6	5 7/8
46.8 mm	US 4	H	47	15	7	6 1/2
47.4 mm	US 4.25	H 1/2	47.5	—	—	7 1/8
48 mm	US 4.5	I	48	15 1/4	8	7 3/4
48.7 mm	US 4.75	J	48.5	15 1/2	—	8 3/8
49.3 mm	US 5	J 1/2	49	15 3/4	9	9
50 mm	US 5.25	K	50	16	—	9 5/8
50.6 mm	US 5.5	K 1/2	50.5	16 1/4	10	10 1/4
51.2 mm	US 5.75	L	51	—	11	10 7/8
51.9 mm	US 6	L 1/2	52	16 1/2	12	11 1/2
52.5 mm	US 6.25	M	52.5	16 3/4	—	12 1/8
53.1 mm	US 6.5	M 1/2	53	17	13	12 3/4
53.8 mm	US 6.75	N	54	—	—	13 3/8
54.4 mm	US 7	N 1/2	54.5	17 1/4	14	14
55.1 mm	US 7.25	O	55	17 1/2	—	14 5/8
55.7 mm	US 7.5	O 1/2	56	17 3/4	15	15 1/4
56.3 mm	US 7.75	P	56.5	18	—	15 7/8
57 mm	US 8	P 1/2	57	—	16	16 1/2
57.6 mm	US 8.25	Q	58	18 1/4	—	17 1/8
58.3 mm	US 8.5	Q 1/2	58.5	18 1/2	17	17 3/4
58.9 mm	US 8.75	R	59	18 3/4	—	18 3/8
59.5 mm	US 9	R 1/2	60	19	18	19
60.2 mm	US 9.25	S	60.5	19 1/4	—	19 5/8
60.8 mm	US 9.5	S 1/2	61	19 1/2	19	20 1/4
61.4 mm	US 9.75	T	61.5	—	—	20 7/8
62.1 mm	US 10	T 1/2	62	19 3/4	20	21 1/2
62.7 mm	US 10.25	U	63	20	21	22 1/8
63.4 mm	US 10.5	U 1/2	63.5	—	22	22 3/4
64 mm	US 10.75	V	64	20 1/2	—	23 3/8
64.6 mm	US 11	V 1/2	65	20 3/4	23	24
65.3 mm	US 11.25	W	65.5	—	—	24 5/8
65.9 mm	US 11.5	W 1/2	66	21	24	25 1/4
66.6 mm	US 11.75	X	67	21 1/4	—	25 7/8
67.2 mm	US 12	X 1/2	67.5	21 1/2	25	26 1/2
68.1 mm	US 12.25	Y	68	—	—	27 1/8
68.5 mm	US 12.5	Z	69	21 3/4	26	27 3/4
69.1 mm	US 12.75	Z 1/2	69.5	—	—	28 3/8
69.7 mm	US 13	—	70	22	27	29

By ToolNeko's independent creator · Updated September 5, 2026. Calculations run in your browser.

Use the chart as a named reference, not a universal promise

This page transcribes the 41 quarter-size rows in the Brilliant Earth international chart updated August 5, 2026, covering inside circumferences from 44.2 to 69.7 mm and US sizes 3 through 13. Its regional column names remain separate because France-style, Germany-style, Japan-group and Italy-style numbers are not one interchangeable “EU size.” A missing conversion stays unavailable.

Measure an existing ring by its inside diameter

Choose a round ring that fits the same finger. Measure straight across the empty inside opening, not from one outside edge to the other. The tool converts that diameter to the corresponding inner circumference and finds the closest literal chart row. Non-round rings and unusual interior profiles need a jeweler's sizing tools.

Measure the intended finger separately

A flat paper strip or flexible tape can estimate finger circumference, but pressure, temperature, time of day, and a larger knuckle can change the reading. Measure at different times and add repeat readings. One reading still produces a reference lookup, but it is labeled as unchecked. Two or three readings must remain within ToolNeko's conservative spread heuristic and point to the same literal row before the page calls them repeatable.

What happens at a boundary or conflict?

The chart has uneven gaps, so this tool compares against the actual midpoint between each pair of published rows. An exact midpoint keeps both rows. Repeat readings that span neighboring rows also keep a range. In Check both mode, the ring and finger estimates are never averaged: matching rows may be combined, neighboring rows remain a boundary, and a larger disagreement triggers a remeasure message instead of a single recommendation.

Fit limits for wide, expensive, or final-sale rings

This is an at-home reference, not a fit guarantee or a substitute for the seller's chart. Wide bands, interior shape, knuckle clearance, and brand construction may change the size that feels comfortable. The tool deliberately does not add a fixed half-size rule, simulate a physical ruler on an uncalibrated screen, or generate an uncalibrated printable sizer. Confirm important purchases with the merchant or a professional finger gauge.

Frequently asked questions

How do I use a ring size chart?

Measure the inside diameter of a round ring that already fits the intended finger, or measure around the finger in millimeters. This tool maps that measurement to the closest row in one named published chart and keeps boundary or conflicting results visible instead of forcing one size.

Is a US ring size exactly the same across every brand?

No. International conversions and fit can vary by chart, brand, ring profile, and width. Results here are references from the Brilliant Earth chart updated August 5, 2026; confirm the seller's own size guide before ordering.

Why should I repeat my ring measurement?

Finger measurements can change with temperature, time, pressure, and the way a strip is held. Add two or three readings to see whether they land on the same published row. ToolNeko's spread check is a conservative remeasurement heuristic, not an industry tolerance.

Can I compare an existing ring with my finger measurement?

Yes. Check both maps the existing ring's inside diameter and the finger circumference separately. It does not assume the two raw measurements must be geometrically equal or average them together. If the reference rows conflict, the tool refuses to select one size.

Should I measure the outside diameter of a ring?

No. Measure the straight inside opening of a round ring. The outside diameter includes the ring material and will overstate the opening.

Does this guarantee that a ring will fit?

No. Knuckle size, band width, ring profile, temperature, and brand construction can change fit. Use the seller's chart or a professional finger gauge for expensive, wide, custom, or final-sale rings.