Ring Sizing Chart

Use this chart to find your US ring size from a measurement in millimeters. If you have a ring that already fits, measure the inside diameter across the middle and match it to the table. To measure your finger directly, wrap a strip of paper snugly around it, mark where it overlaps, and measure that length in millimeters against the inside circumference column.

US Ring Size	Inside Diameter (mm)	Inside Circumference (mm)
4	14.8	46.8
4.5	15.2	47.9
5	15.6	49.3
5.5	16.0	50.6
6	16.5	51.9
6.5	16.9	53.1
7	17.3	54.4
7.5	17.7	55.7
8	18.1	57.0
8.5	18.5	58.3
9	19.0	59.5
9.5	19.4	60.8
10	19.8	62.1
10.5	20.2	63.5
11	20.6	64.6
11.5	21.0	65.9
12	21.4	67.2
12.5	21.8	68.5
13	22.2	69.7

Measurements are standard US ring sizing and are approximate. If you fall between two sizes, choose the larger one, and measure at the end of the day when fingers are at their largest.

About adjustable rings

An adjustable ring has an open or coiled band that gently expands and contracts, so it fits a range of sizes rather than one exact size. You do not need a precise measurement for an adjustable ring — use the chart above to find your general size, then open or close the band slightly for a comfortable fit. Adjust gradually and avoid repeated wide bending, which can weaken any metal over time.