Ring Size Guide

How U.S. ring sizes work

U.S. ring sizes are a scale of inside diameters. Size 7, the most common women's size, is about 17.3 mm across the inside, or 54.4 mm around. Each whole size adds about 0.8 mm to the diameter and about 2.5 mm to the circumference, and half sizes sit halfway between.

The scale is small: half a size is only about 1.3 mm of circumference, which is why a ring that is half a size off can feel loose or tight. Take the few minutes to measure carefully before you order, especially for a ring made in your size.

Approximate size chart

Inside diameters for common U.S. sizes: size 4, 14.9 mm; size 5, 15.7 mm; size 6, 16.5 mm; size 7, 17.3 mm; size 8, 18.2 mm; size 9, 19.0 mm; size 10, 19.8 mm; size 11, 20.6 mm; size 12, 21.4 mm; size 13, 22.2 mm.

To use the chart with a ring that already fits the right finger, measure straight across the inside of the band with a millimeter ruler and find the nearest value. Measure the inside, not the outside, and use a ring with a similar width to the one you plan to buy.

Measuring at home

The most reliable home method is a ring that already fits the same finger, measured as above. The next best is a strip of paper or a non-stretch string: wrap it snugly around the base of the finger, mark where it overlaps, lay it flat, and measure the length in millimeters. Compare that circumference to 54.4 mm for size 7, adding or subtracting 2.5 mm per size.

The most accurate option of all is a jeweler's sizing ring set. Most local jewelers will size a finger for free in a minute. Plastic adjustable sizers work too, but pull them snug over the knuckle to check.

When and how to measure

Fingers swell with heat, salt, exercise, and the time of day, and shrink in the cold. Measure at the end of the day at a normal room temperature, and measure three times on different days if you can.

The ring has to pass over the knuckle and still stay on the base of the finger. If your knuckle is larger than the base, choose the size that slides over the knuckle with a little resistance. Your dominant hand is often about half a size larger than the other, so measure the finger the ring will actually be worn on.

Width and comfort fit change the size

A wide band covers more of the finger and feels tighter than a thin one in the same size. For bands about 6 mm and wider, many people go up half a size from their usual size.

Comfort-fit bands are rounded on the inside, so they slide over the knuckle more easily; many people wear a quarter to a half size smaller in comfort fit than in a standard-fit band. Stacks of several rings on one finger also feel tighter than one ring alone. Product pages list the band width and fit for each option.

Made in your size vs stocked sizes

Some rings are made in the size you choose. The ring is sized before it ships, which takes extra processing days, and because it was made for you it is final sale under our Returns Policy. Other rings ship in exact sizes that are already in stock; the size you pick is the size that ships.

We do not resize rings after delivery, and post-delivery resizing by anyone else is not covered by the Limited Warranty. Tungsten, titanium, cobalt, and ceramic bands generally cannot be resized at all, so treat those sizes as final.

Sizing a surprise

For a surprise, borrow a ring the person wears on the same finger and measure its inside diameter, or press it into a bar of soap to record the size. A ring worn on a different finger is only a rough guide, since fingers vary by a size or more.

If you truly cannot find out, choose a style that ships in stocked sizes rather than one made to order, and pick a common size for the finger. For engagement rings, the engagement ring buying guide covers the rest of the decision.

Shop by size

On the ring aisles you can filter by the size you wear. The filter shows rings made in any size plus rings stocked in your exact size, and an "Exact stock size only" switch narrows the list to rings already in that size.

The size filter is on wedding bands, engagement rings, fashion rings, lab grown diamonds, men's jewelry, and birthstone jewelry. For wearing several rings together, see how to stack rings.

Common questions

What is the most common ring size? In the United States, women most often wear sizes 6 to 7 and men most often 9 to 10, but individual fingers vary widely, so measure rather than guess.

Should I size up or down if I am between sizes? For wide bands, size up. For thin bands, many people choose the smaller size so the ring does not spin. For comfort-fit bands, the smaller size often works because the rounded inside slides over the knuckle more easily.

Do fingers change size over time? Yes. Weight changes, pregnancy, age, and joint changes can move a finger by a size or more, and fingers swell in hot weather and shrink in cold. A ring that fits comfortably in the evening in a mild room is the best guide.

Can I use a printable ring sizer? Yes, if it prints at exactly 100% scale. Check the printed ruler with a real ruler before you use it, since printer scaling is the most common source of error.

My ring spins on my finger. What can I do? A slightly loose ring, or a top-heavy one, will turn. A local jeweler can add sizing beads or a small insert that holds it upright, though an altered ring can no longer be returned.