Finding the right ring size is one of the most important steps when choosing a ring. A ring that's too tight can be uncomfortable, while one that's too loose is at risk of slipping off. Whether you're shopping for yourself or planning a surprise, understanding how to measure a ring size ensures a comfortable, confident fit. Our easy-to-follow ring size conversion chart helps you match measurements across the U.S., U.K. and other international sizes. Read on to learn how to measure your ring size at home, plus how to use the chart to find the perfect fit.

If you're still unsure of your exact ring size, our free plastic ring sizer offers another accurate way to measure at home. It's reusable and can arrive within just a few days of ordering. You can request the free ring sizer by simply filling out the request form on our site, and we'll mail it to your address of choice.

Once it arrives, simply slide your finger into the circle until a size feels right. We recommend trying a half size up or down to find your precise fit. The right ring size should be snug enough that the plastic ring doesn't slip off, but loose enough to slide over the knuckle.

If you're wondering how to measure a ring size at home without a dedicated sizer, this simple method can help you find an accurate fit using everyday items. It's also an easy way to keep a surprise when shopping for someone else—just borrow one of their rings or ask a close friend or family member for help.
This at-home approach requires only a piece of string, a ruler, a pen and a small piece of paper. Follow these quick steps to learn how to measure ring size accurately:

If you're adjusting the fit of an existing ring, professional resizing ensures it feels just as good as the day you wore it. Whether it's an engagement ring, wedding ring or fashion piece, resizing can help restore that perfect fit. Sizing a ring depends on whether the band needs to be made larger or smaller. To increase the size, a jeweler carefully adds a small piece of matching metal, solders it into place and polishes the band to a seamless finish. To make the ring smaller, a tiny section of the band is removed, then reshaped and refinished. Our expert jewelry makers at Blue Nile follow strict quality standards throughout the entire ring resizing process.

Don't worry if your new ring doesn't fit quite right, it happens more often than you'd think. The first step is to try the ring on a few times throughout the day, since finger size can shift slightly from temperature change and activity. If it still feels too loose or snug, we'll guide you through the best next steps. At Blue Nile, we offer complimentary resizing for most engagement rings and wedding rings within the manufacturer's recommended range during the first year. You can also take advantage of our 30-day exchange policy if you need a different ring size.

Certain ring styles cannot be resized due to their design. In these cases, an icon will appear on the product detail page under the ring size selection.
For example, diamond and gemstone eternity rings with a specific number of gemstones per finger size, milgrain or ornate bands, silver rings or rings with alternative metals such as tungsten cannot be resized.
We're happy to exchange your ring for another in the correct size within 30 days of purchase. It's important to note that should you opt for an exchange, your new ring may contain fewer or more gemstones, diamonds or a different precious metal weight, which may cause an increase or decrease in the price.