How to Measure Your Ring Size: Conversion Chart & Ring Sizer

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.

FIND YOUR RING

Finding your size at home is quick and simple with our printable ring size chart. It's an easy way to get an accurate fit before ordering, and includes a ring conversion guide across different sizing systems. Just download the guide and follow the steps below:

1. Print the chart at 100% scale: Make sure the page isn't resized or "fit to page." A reference line is included to confirm the chart is printed to scale in millimeters (mm). 

2. Find a ring that fits comfortably: Choose one you already own that matches the finger where you or your loved one will wear the new ring. 

3. Match your current ring to the circles: Place it over the printed circles until the inside edge of your ring lines up perfectly with one of the circles. The numbers shown reflect the inside diameter, which matches your ring size. 

4. If your ring falls between sizes, choose the larger one: A slightly larger fit will feel more comfortable, especially for wider rings. 

Be sure to keep the bandwidth in mind. Since wider styles can feel tighter, consider going up half a size for a better 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.

How to Measure Ring Size with String, Paper and a Ruler

 

If you’re wondering how to measure 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: 

1. Wrap the string or paper around the base of your finger. 

2. Mark the point where the ends meet with a pen.  

3. Measure the string or paper with a ruler in millimeters (mm), then divide the number by 3.14 (or pi) to find the ring's diameter. 

4. Match your result to the closest size on the ring size chart to determine your correct ring size.  

Measure Your Ring Size at Home:

 

1. Wrap string around finger. 

2. Mark where the ends meet. 

3. Measure the length. 

4. Match your result.

Getting the right fit isn't just about the measurement—it's about how your ring feels day to day. Use these helpful tips to ensure lasting comfort and confidence in your choice: 

- Use another ring as a guide: Measure the inside diameter of a ring that fits well using a tape measure and compare it to our printable ring sizer or ring size chart. 

- Check the fit: Your ring should feel snug enough not to slip off yet loose enough to slide comfortably over your knuckle. 

- Account for larger knuckles: If your knuckle is wider than the base of your finger, measure both and choose a size in between for the best fit.

- Measure at the right time: Finger size can vary with temperature, time of day and even which hand you use most. It's better to take your measurement at the end of the day when your fingers are warm and slightly larger. 

- Measure more than once: Repeat the process three to four times to confirm the results.

Are you planning a surprise proposal or gift? It's possible to find the right ring size without giving it away. The easiest method is to borrow one of their rings—preferably one they wear on the same finger—and use our printable ring size chart to measure it. 

If borrowing isn't an option, enlist the help of a close friend or relative who can subtly ask about their ring size without raising suspicion. You can also trace the inside of their ring on paper or measure it with a ruler to compare against our chart. These discreet hacks make it simple to get a perfect fit while keeping your plans secret. 

Be sure to check out our unique engagement ring guide to find something extraordinary for that special someone. 

While the most accurate method for finding a ring size is a printable ring size chart, there are other at-home measuring techniques you can try. Here are a few more reliable ways to find your perfect fit.

- Assessing existing jewelry: Using a ring that already fits the intended finger, match it to our printable ring size chart or measure its inside diameter to find the correct size. 

- Measuring your finger: With just a string, ruler and pen, you can measure directly at home by wrapping the string around your finger and marking where the ends meet. 

- Using a plastic ring sizer: Our free tool is simple to order online, use and measure your finger directly.   

For extra accuracy, try more than one approach and compare results using our printable ring size chart. Keep in mind that your ring size can change temporarily, so it's ideal to measure more than once at different times in the day. In the end, the best method is the one that works most comfortably and conveniently for you or the person you're surprising. 

Knowing the most common ring sizes can help you confidently start your search, especially if you're buying a ring as a gift or planning a surprise proposal. Use these averages as a helpful starting point before measuring for the most accurate fit.

Women's ring sizes: 

- Average size: 3–9 

- Most purchased sizes: 5–7 

- Most popular size: 6

Men's ring sizes: 

- Average size: 6–13 

- Most purchased sizes: 8–10½ 

- Most popular size: 9 

If you don't see your size listed, our experts can help with special orders and custom sizing. You can also use one of our at-home methods to find the correct size.

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 to restore its original appearance.

Our expert jewelry makers at Blue Nile follow strict quality standards throughout the entire process. After resizing, each ring is cleaned and polished to ensure a flawless finish and comfortable fit.

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.