How to find the perfect engagement ring size

Forever guides


Preparing to propose to your true love is a significant step. But before you can find the perfect ring, it is important to determine your partner’s ring size accurately. Use the tips below and our printable ring size chart to help ensure that your engagement ring choice fits well on your loved one's finger first time. 

Before printing our guide go to your ‘print settings’ and ensure that the ‘page scaling’ options are not set to scale or shrink. After printing, you can check the guide has printed correctly using a ruler. Please note that ring size measurement will not be accurate if this step is not completed properly. Further guidance is included within the printable size guide.

How to measure your
partner’s ring size

An engagement ring is the ultimate symbol of commitment and everlasting love. While there are many ways to surprise your partner with a romantic proposal, here is how to subtly discover their ring size for the perfect proposal moment.

Borrow an existing ring

One of the easiest ways to learn your partner’s ring size is to take a look at the rings they already own. Comparing the size of these rings to the printable De Beers Forevermark ring size chart will allow you to discover the size you need to buy. If possible, you may also want to consider taking your partner's ring into the nearest Authorised De Beers Forevermark Jeweller for further expert advice.

Do be sure that the ring you are borrowing fits the ring finger – in most Western cultures engagement rings are traditionally worn on the fourth finger of the left hand. 

Another factor that can easily go amiss is the difference between the right and left hand. The dominant hand usually tends to be a little bigger.

Bar of soap ring trick 

If you’re concerned your partner may notice one of their rings has gone missing, the bar of soap trick may be a more effective method of finding out the ring size. Discreetly take the pre-owned ring and press it into a bar of soap to create an imprint of the ring size. Ensure that you rinse and dry the ring before putting it back exactly where you found it to avoid raising suspicion. The imprint can then be measured against the De Beers Forevermark ring size chart to identify an accurate ring size. Alternatively, you could take the bar of soap into your nearest Authorised De Beers Forevermark Jeweller  for assistance.

If you don’t have a bar of soap to hand, download and print our De Beers Forevermark ring size chart and place the ring directly onto the closest fitting circle to identify an accurate ring size.

Talk to friends and family

You know your partner inside out but when it comes to finding out their ring size, don't hesitate to ask for help from other people in their life - such as friends and family. It may be that they already know what ring size they wear, or they may be able to investigate on your behalf. It's often a more discreet route to explore.

Take this opportunity also to gather deeper insights into what your partner might be looking for in an engagement ring, whether that be the shape of the diamond or the ring setting. It will also help ease your mind, and make the decision-making process less intense. 

Involve your partner 

Choosing an engagement ring is undoubtedly one of the most momentous steps in your relationship. The ring you choose will not only symbolize your enduring commitment to each other, but it will also be an eternal reminder of the love you share. For these reasons, it is essential both of you are just as pleased with what the ring represents.

Why not break traditions and take your partner engagement ring shopping? Purchasing the ring together could be a memorable experience in itself - why not spend the afternoon window shopping and trying on different designs until you find the perfect diamond together?

Useful hints

There are a few environmental and physical factors that should be taken into consideration before deciding on the size of the ring you want to buy, but remember that when it comes to guessing your partner’s ring size, guess on the large side as it’s easier to size a ring down. We also recommend measuring a finger 3 or 4 times to avoid erroneous reading.

Average ring sizes

Keep in mind the average ring size range for women is between 49 and 54 (Europe), while sizes commonly range from 57 and 62 (Europe) for men. If you have no other information available, it's best to choose between these ranges.

Thicker ring bands (larger than 6mm) will fit tighter. It is advised to always go for half a size up when purchasing a thicker band, for the ring to be comfortable.

Time of day

An ideal time to measure their finger size is in the evening. Most people's fingers tend to be at their largest in the evening and smaller in the morning. Measuring your partner's finger size in the evening will guarantee a comfortable fit.

Optimal temperature

Fingers tend to react to temperatures, and can change size depending on the weather. According to Authorised De Beers Forevermark Jeweller Carat Co., the biggest the finger is ever going to be is an extra quarter. The cold winter air will shrink fingers while the opposite happens in summer or when it’s warm and humid. Avoid measuring finger size outside in the very cold or very hot. Only measure when your finger is at room temperature.

Fingers expand and contract

Other factors can cause fingers to grow such as exercising, water retention, pregnancy, ageing, and arthritis. Weight loss and low temperatures can cause fingers to decrease in size.

Resizing your ring

Rings can typically be resized up to two sizes larger or smaller, depending on your setting and the type of metal. Resizing a ring too many times will weaken the metal and could eventually damage the ring. Whether you need to resize your ring up or down the resizing process is usually a simple one.


How to resize a ring

Increasing your ring size
A ring can successfully be stretched to a maximum of half a size larger, and if the required size of the ring exceeds this specification additional metal will be soldered into the middle of the band. This will help preserve the ring’s strength.

Decreasing your ring size
In order to make a ring smaller the jeweller will carefully make a small incision in the centre of the band removing the excess metal until the ring is the desired size.

Once the band has been re-joined it will be carefully cleaned to remove any signs of oxidation caused during the soldering process. It will then be polished ensuring a smooth finish and leaving no signs of alteration, so that your ring will look good as new. 


Eternity rings

Eternity rings are set with a continuous line of diamonds, and each diamond has to be identically cut and of the exact same size. To resize an eternity ring, a small diamond will need to be added to the band or removed, and so there must be correspondence between the size of the diamond and the size that the ring needs to be increased or decreased by.

Tension set rings

Tension set rings have a very modern look as they hold the diamond in place by pressure rather than prongs or bezel. Tension set rings can be resized as long as the tension setting is properly secured and thoroughly checked.

Most tension set rings can be resized but the more intricate and detailed the ring the more complex it will be. For more information on resizing tension set rings, talk to your nearest Authorised De Beers Forevermark jeweller. 


It is better to guess a ring size on the larger side because it is easier to size a ring down than up if you guess incorrectly. It is also better for the ring to fit slightly bigger than too small so that it does not fit at all.

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Now, Forever

We are believers in Forever. Through the twists and turns, the ups and downs, everyone goes on a different journey towards true love. Every step you take now, is a step towards your Forever.