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Ring Size Guide: How to Find Your Ideal Ring Size

By Mike Fried,

Bottom Line Recommendation:

For the best ring size measurement, we recommend ordering a free ring sizer from either Blue Nile or James Allen. These ring sizer tools work better than paper and string which can both stretch—causing an inaccurate measurement. You can also measure the inside diameter of an existing ring and compare it to a ring sizing chart like the one below. 

We also suggest buying a diamond ring from a reputable vendor who offers a complimentary ring resize like James Allen and Blue Nile.

Wondering what your ring size is or how to figure out ring size? Whether you’re shopping for the perfect engagement ring or an anniversary ring or eternity band, you’ll need to know the correct ring size. And if you’re planning a surprise proposal, you’ll need this information well in advance.

Luckily, there are several ways to find the ideal ring size for your special someone. While you can always get the ring resized if it’s not quite right, the excitement of wearing the ring proves better if you have the correct size from the start.

Our guide includes a ring size guide, insider tips on measuring and the best places to buy a diamond ring once you know the size.

How to Determine Ring Size

To determine your partner’s ring size or yours, order a free ring sizer, print a sizing tool, or measure a current ring. These sizing methods help determine the ring size for both men and women.

To help you with the diamond buying process we lean on our expertise and experience. The author of this article, our CEO, Mike Fried has over 20 years of experience in the diamond industry. Mike started from the bottom, sorting and evaluating hundreds of thousands of diamonds to learn every facet (pun intended) of diamond quality and value. Mike followed that up by spending years buying and selling diamonds on the wholesale market as well as selling tens of millions of dollars worth of diamonds to diamond retailers.
  • For the most accurate method, order a free ring sizer from James Allen or Blue Nile. Either website will send you a free plastic ring sizer in the mail. The GIA recommends allowing the person to slide the ring sizer on and off to check that it comfortably fits over their knuckle.
Ring Size Set Example

Experts suggest avoiding using paper or string to measure ring size. Both materials can stretch or twist, causing your ring measurement to be inaccurate. James Allen also offers a complimentary online sizing tool here.  If you feel like you want something nicer because you’ll use it more than once, there are ring sizer tools being sold on Amazon for a few bucks.

  • Match the size of an existing ring—whether that’s a class ring or an engagement ring. Measure the inside diameter and compare it with a plastic ring sizer or printable ring sizer chart like the one below from Blue Nile.
  • Another option is to go to Amazon and look for a ring size measuring stick. This can be very useful even after your engagement when you decide to surprise your partner with another ring at any point in your life together.
  • Measure the wearer’s ring finger with paper and compare it with a ring sizing chart. You can use a free printable ring sizer or a thin piece of paper (however, we suggest a free plastic ring sizer ahead using these methods). Wrap the piece of paper around the finger, then mark the spot where the paper overlaps. Measure the length with a ruler and compare to a ring size guide (below). If he or she is a heavy sleeper, and you want to measure in sneaky fashion, try wrapping a string around their ring finger during the night. Pinch the point where the ends meet, then compare the measurement to the chart.
  • If you don’t want to use the methods above for determining ring size, you can visit a jewelry store for professional measurement, or have a close friend or family member gather the ring size information. Parents or friends may have purchased jewelry for your partner in the past, or have access to their jewelry collection. They can also covertly ask their ring size (just in case you ‘happen’ to propose).

    Deal Alert: Get 30% off lab-grown diamonds during a limited time sale at James Allen.

    Your Engagement Ring Can Be Resized

    Remember that not knowing the ring size doesn’t have to spoil your proposal plan. Go with your best estimate using the ideas above, and opt for a half size up when in doubt.

    The ring can also be resized after the proposal. Most diamond sellers, like Blue Nile and James Allen, offer complimentary ring resizing within a certain time frame. Be sure to know ahead of time what the free resize period is at your particular vendor so you don’t miss out on this service.

    Ring Size Chart (Keep this Handy Throughout the Process)

    A ring sizing chart can help you determine the ring size—no matter which measuring method you use. Based on the ring size circumference or diameter, you can find the size that matches.

    As mentioned above, we suggest ordering a free ring sizer from Blue Nile or James Allen. Or you can get one of the ring sizer tools from Amazon.

    Size Measuring Stick

    Any of these tools help you measure a finger or an existing ring.

    No matter how you receive your measurement, you can use the chart below to determine the proper size.

    If you have a measurement for the ring’s circumference, use the circumference column.

    If you have a measurement for a ring’s diameter, use the diameter column.

    The chart below is both a men’s ring size chart and a ring size chart for women.

    International Ring Size Chart for both Men & Women

    Circumference (mm)Diameter (mm)UK, Europe, AustraliaUnited States & CanadaChina, Singapore, JapanHong KongSwitzerland
    44.214.1F3464
    44.814.3F  1/2 5 5  1/4
    45.514.5G3  1/2 7.5 
    46.114.7G  1/2 6 6  1/2
    46.814.9H479 
    47.415.1H  1/2   7  3/4
    48.015.3I4  1/2810 
    48.715.5J   9
    49.315.7J  1/25911 
    50.015.9K   11  3/4
    50.616.1K  1/25  1/21012 
    51.216.3L   11  3/4
    51.916.5L  1/26111312  3/4
    52.516.7M 12  
    53.116.9M  1/26  1/21314.514
    53.817.1N    
    54.417.3N  1/27141615  1/4
    55.117.5O    
    55.717.7)  1/27  1/2151716  1/2
    56.317.9P    
    57.018.1P  1/2816 17  3/4
    57.218.2   18 
    57.618.3Q    
    58.318.5Q  1/28  1/21719 
    58.918.8R   19
    59.519.0R  1/291820.5 
    60.219.2S   20  1/4
    60.819.4S  1/29  1/21922 
    61.419.6T   21  1/2
    62.119.8T  1/2102023 
    62.720.0U 21  
    63.420.2U  1/210  1/2222422  3/4
    64.020.4V    
    64.620.6V  1/2112325 
    65.320.8W   25
    65.921.0W  1/211  1/22426 
    66.621.2X    
    67.221.4X  1/2122527.7527  1/2
    67.821.6Y    
    68.521.8Z12  1/226 28  3/4
    69.122.0Z  1/2    
    69.722.2 132730 
    70.422.4Z+1    
    71.022.6 13  1/2   

    *Data from the Blue Nile International Ring Size Chart

    Average Ring Size for Men

    The average ring size for men is between 8 and 10.5. Men’s ring sizes usually range from 8 to 14, with size 9 being the most common.

    Average Ring Size for Women

    The average ring size for women is between 5 and 7. Women’s ring sizes typically range from 3 to 9, with size 6 being the most common.

    Pro Tips for Ring Finger Measuring

    Measuring ring size is pretty straightforward, but you should still keep in mind the following tips to ensure your measurement is as accurate as possible.

    • Be sure the finger is at normal or slightly elevated body temperature, as fingers shrink and expand when hot or cold. The best time for the most accurate sizing is near the end of the day when the fingers are warm. When the hands are cold, like they often are in the morning, the fingers will measure smaller.
    • Measure the finger three to four times to prevent inaccuracies.
    • Use a plastic ring sizer like this one from Blue Nile rather than a piece of paper or string, as these can bend or stretch and create inaccuracies.
    • Measure the finger you’re intending to wear the ring on, such as the engagement ring finger. Left-hand and right-hand ring fingers can differ in size.
    • If the knuckle is noticeably larger than the base of your finger, record both measurements and choose a ring size that’s in-between the two. The ring should slide over the knuckle, but shouldn’t be so loose that you’ll risk having it slip off or move around excessively.
    • It’s critical that the ring fits tightly over the knuckle to prevent the ring from falling off. It shouldn’t be too tight, though, where blood flow is restricted.
    • Wider bands (those 6mm or wider) tend to fit more snugly than other setting styles. Consider ordering a quarter to a half size larger with a wide band.

    Where To Buy a Diamond Engagement Ring

    Now that you have a plan for how to measure ring size, you can focus on finding the most stunning diamond ring at the best price. The first step is finding a reputable and reliable vendor who offers well-cut diamonds at excellent prices.

    Throughout our years of experience in the diamond industry, we’ve vetted several diamond dealers. We have a consistent pulse on the companies you can trust.

    For the best diamond cuts at an exceptional value, we recommend:

    James Allen

    • Incredible diamond imagery
    • Focuses on customer experience
    • Appealing prices
    • High quality certification (GIA & AGS)

    Blue Nile

    • Emphasizes remarkable diamond quality
    • Offers the largest online inventory of diamonds and settings
    • Known for beautiful jewelry settings
    • High quality certification (GIA).

    Brian Gavin Diamonds

    • Offers only the best cut diamonds
    • Presents super-ideal cuts with the “Brian Gavin Signature” Hearts & Arrows collection
    • High quality certification (GIA & AGS)

    How to Choose a Beautiful Diamond Ring

    Our goal is for you to end up with the most exceptional diamond ring at an exceptional price. To achieve this, you need to keep in mind important components when assessing a diamond’s beauty and value. You want to spend in the areas that matter, and scale back in areas that’ll go unnoticed.

    We recommend closely reviewing the diamond yourself or having a diamond expert assist you.

    Be sure to follow our expert recommendations:

    • Certification: Ensure any diamond you’re considering has a GIA certificate.
    • Diamond shape: Select a Diamond Shape that’s appealing to you. Shape is usually based on personal style.
    • Ring setting: Do you want a vintage, halo or solitaire setting? Check out our engagement ring setting guide to determine the style that’s best for you.
    • Diamond cut: Only consider diamonds with an ideal cut or an Excellent grade on the GIA scale. A well-cut diamond will maximize the brilliance and fire more than any other feature.
    • Diamond clarity: Consider diamonds of VS1 and VS2 Clarity grade. These levels of clarity offer you the greatest value for what can be seen by the naked eye.
    • Diamond color: Narrow your search to diamonds in the nearly colorless range of G-I. To the naked eye, these diamonds appear just as clear as those in the D-F range but cost significantly less.
    • Online diamond dealer: Select a diamond from a reputable diamond vendor with high-quality cuts and years of experience like Blue NileBrian Gavin Diamonds and James Allen.
    • Expert assistance: Lean on the diamond experts. Ask for the complimentary help of an expert to review and search for high-quality diamonds. Check out resources like our 1 Carat and 2 Carat Buying Guides.

    Reach out to us today to begin your complementary diamond search.

    James Allen James Allen is the leader in online diamond sales. Their imaging technology is the same as inspecting a diamond with a jeweler's loupe. They have the largest exclusive loose diamond inventory online and fantastic prices. They also have the nicest collection of lab-created diamonds online.
    What we love about them:
    • No questions asked returns within 30 days of shipment. James Allen will send you a paid shipping label to return the ring.
    • Lifetime Warranty
    • Free International Shipping
    • Free prong tightening, repolishing, rhodium plating and cleaning every 6 months
    • Provide insurance appraisals
    • One free resizing within 60 days of purchase
    • Free ring inscriptions
    • Best-in-class high quality imagery of all diamonds in stock
    • 24/7 Customer Service
    • Best-in-class packaging
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    Blue Nile Blue Nile is the largest and most well-known internet jewelry seller. They have a very large exclusive online inventory. Their high-quality images are catching up to James Allens' and their prices are amazing. 
    What we love about them:
    • No questions asked returns within 30 days of shipment. Blue Nile will send you a paid shipping label to return the ring.
    • Lifetime Warranty
    • Free Shipping
    • Free prong tightening, repolishing, rhodium plating and cleaning every 6 months
    • Provide insurance appraisal
    • One free resizing within the first year of purchase
    • High quality images of about half of their diamonds
    • 24/7 Customer Service
    • 100% credit towards future upgrades (must be at least double in value)
    • Best in class fulfillment
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    About the author

    Mike Fried Mike Fried Mike Fried has over 25 years experience in the diamond industry working with Leo Schachter Diamonds, Moshe Namdar Diamonds, and joining The Diamond Pro in 2007. He is recognized as an industry expert and has been quoted in publications such as Us, People, Page Six, The Next Web and more.

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