Ring Size Chart: How to Measure Your Ring Size at Home

Ordering a ring online is easy until you hit the "select size" dropdown. Measure once with the methods below and you'll never have to guess again. This guide covers the full US ring size chart in millimeters, three ways to measure at home, and the mistakes that cause most wrong-size orders.

US Ring Size Chart (Diameter & Circumference in MM)

Every US ring size corresponds to an exact inside diameter and circumference. If you can measure either one, this chart gives you your size:

US Size	Inside Diameter (mm)	Inside Circumference (mm)
4	14.9	46.8
4.5	15.3	48.0
5	15.7	49.3
5.5	16.1	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	63.4
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

Method 1: Measure a Ring You Already Own (Most Accurate)

1. Pick a ring that fits the same finger on the same hand you're shopping for.
2. Lay it on a ruler and measure the inside diameter: inner edge to inner edge, in millimeters.
3. Match the diameter to the chart above. If you land between two sizes, choose the larger one.

This method wins because it measures a fit you already know is comfortable, rather than a finger whose size changes during the day.

Method 2: The String (or Paper Strip) Method

1. Cut a thin strip of paper or a piece of non-stretchy string.
2. Wrap it snugly around the base of your finger: snug enough that it won't spin, loose enough to slide over the knuckle.
3. Mark where it overlaps, then measure the length in millimeters.
4. That number is your circumference. Find it in the third column of the chart.

Tip: repeat three times and average the results. String stretches and paper shifts, so a single measurement can be off by half a size.

Method 3: Use a Ring You Own + a Round Sizer Object

No ruler with millimeters? Find a circular object that slips perfectly inside a well-fitting ring (a dowel, marker, or rolled paper), mark the spot, and measure that diameter against any online mm scale. It's a rough method, so use it only to sanity-check one of the first two.

5 Rules for Getting the Fit Right

• Measure at the end of the day. Fingers are smallest in the cold morning and largest in evening warmth, and end-of-day is closest to average wear.
• Mind the knuckle. If your knuckle is noticeably larger than the base of your finger, size for a point midway between the two measurements.
• Wide bands run tight. For bands 6mm or wider (like statement rings), go up half a size from your measured size.
• Each hand is different. Your dominant hand typically runs about half a size larger.
• Stacking changes things. If you're layering stackable rings, keep them all at your true size, because stacked rings shouldn't be sized up, or they'll spin.

What If You're Between Sizes?

Go up. A slightly loose ring can be worn with a sizer insert; a tight ring can't be worn at all. This matters most for eternity-style bands, which usually can't be resized because stones circle the full band. Check our eternity rings in your confirmed size instead of guessing.

Ring Size FAQ

What's the most common ring size?

For women in the US, sizes 6 to 7 are the most common; for men, 9 to 10. But "common" is no substitute for measuring, since hand sizes vary far more than shoe sizes.

Can sterling silver rings be resized?

Most plain sterling silver bands can be resized up or down about one size by a jeweler. Rings with stones all the way around (eternity bands) and tension settings generally cannot. See our guide to 925 silver marks to identify what your ring is made of.

Do fingers change size?

Yes. Temperature, salt intake, exercise, and time of day all move finger size by up to half a size. That's why the "measure three times, average it" rule exists.

Is ring size the same in the US and other countries?

No. The US uses numeric sizes (4–13), the UK uses letters, and much of Europe uses the circumference in millimeters directly. The mm columns in the chart above are universal, so when in doubt, work in millimeters.

Sized up and ready? Browse our sterling silver rings, gold rings, and best sellers: real 925 silver at closeout prices, shipped fast from Los Angeles, where we've been since 2006.