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How to measure ring size

At 77 Diamonds, we understand how important finding the perfect ring size is to you. Whether you are looking to purchase for yourself or for your partner, we are happy to provide all the help you need.

Ring Size - Video placeholder
Jump to:
  • Visit our Showrooms
  • Measuring your ring size at home
  • Ring size chart
  • Measuring size for a surprise gift or proposal
  • Ordering the wrong ring size
  • Useful links

Visit our Showrooms

In order to get the most accurate results, the best option is to have your size measured at one of our showrooms in London, Manchester, Berlin or Frankfurt.

Trying on a ring is just like trying on shoes: you need to get the size right. Our team of professional jewellers will have you test a series of different ring sizes to find the most comfortable option for the ring you are looking to purchase.

Measuring your ring size at home

There is much advice online on how to measure your ring size at home. Perhaps you even have heard of methods such as using pieces of string or paper. The reality is these methods are all highly inaccurate and may show completely distorted results, which would be regrettable, especially when planning a surprise proposal.

How do we know this? Simply because we’ve tried and tested them ourselves. At 77 Diamonds, we want to give you the most honest advice so you have less to worry about.

Order a ring sizer

As you will be measuring your finger yourself, there is always a risk of inaccuracy. Follow these steps on how to use our ring sizer:

  1. Place the ring sizer on the chosen finger and tighten until it sits comfortably. The ring sizer shouldn’t be loose enough to turn on your finger nor too tight that it becomes impossible to move. If you feel a slight pinch, you may want to loosen the sizer a little.
  2. Check if you can move the ring sizer over your knuckle. There should be a slight pull or struggle when doing so, but you should still be able to remove it without altering the size.


  • You should always try your measurement three or four times for better accuracy.
  • Your fingers tend to swell in the day and are larger towards the evening. To avoid any discomfort, we recommend you measure your fingers in the evening.
  • Ring size may also vary according to temperature. Cold weather can make your fingers slightly shrink in size.
  • If your measurement falls between two sizes, always opt for the larger size to ensure better comfort.

Use a ring you already own

The second do-it-yourself method is to measure a ring that already fits your finger. If the existing ring fits you well, the new one should too, provided your measurement is accurate.

  1. Find a ring that fits comfortably without being too loose. Choose one you wear on the same finger you’ll wear the new ring to get the best results. Do not choose a misshapen, ornate or wide-banded ring as this will result in inaccurate measurements.
  2. Print out the ring size cutout below in A4. Check the document is scaled to 100%.
  3. Cut out the ring sizer by following the dotted line. Carefully glue the grey tab under the opposite side of the ring sizer, so the two edges neatly overlap. We suggest using glue or double-sided tape. You will find arrows on either side of the sizer. Be sure to make these arrows meet for better accuracy.
  4. You’ll end up with a cone-shaped paper cutout. Slide the ring along the cone until it sits comfortably. Your size will be indicated on the first line the ring reaches.
  5. If your ring sits between two sizes, you can order a half size. If you are planning a proposal, however, we recommend you opt for the largest size.
  6. Please keep in mind these home measurements are for guidance only as they may hold inaccurate results if not handled properly.

Ring size chart

Check your UK ring size below. You can also enter your measurement to see international size conversions.

UK USA French / German Italian Circumference (mm) Diameter (mm)
A 39.00 37.70 12.00
  39.50   38.33 12.20
B   40.00   38.96 12.40
0.75 40.80   39.58 12.60
C 1.25 41.00   40.53 12.90
1.50 41.25 1.00 41.15 13.10
D 1.75 42.00 2.00 41.78 13.30
2.00 42.50 2.50 42.41 13.50
E 2.25 43.50 3.50 43.04 13.70
2.50 44.00 4.00 43.67 13.90
F 2.75 44.50 4.50 44.30 14.10
3.00 45.00 5.00 44.92 14.30
G 3.25 45.50 5.50 45.55 14.50
3.50 46.00 6.00 46.18 14.70
H 3.75 47.00 7.00 46.81 14.90
4.00 47.50 7.50 47.44 15.10
I 4.25 48.00 8.00 48.07 15.30
4.50 48.50 8.50 48.69 15.50
J 4.75 49.50 9.50 49.32 15.70
5.00 50.00 10.00 49.95 15.90
K 5.25 50.50 10.50 50.58 16.10
5.50 51.00 11.00 51.21 16.30
L 5.75 52.00 12.00 51.84 16.50
6.00 52.50 12.50 52.46 16.70
M 6.25 53.00 13.00 53.09 16.90
6.50 54.00 14.00 53.72 17.10
N 6.75 54.50 14.50 54.35 17.30
7.00 55.00 15.00 54.98 17.50
O 7.25 55.75 15.75 55.61 17.70
7.50 56.25 16.25 56.23 17.90
P 7.75 57.00 17.00 56.86 18.10
8.00 57.25 17.25 57.49 18.30
Q 8.25 58.00 18.00 58.12 18.50
8.50 58.50 18.50 58.75 18.70
R 8.75 59.50 19.50 59.38 18.90
9.00 60.00 20.00 60.00 19.10
S 9.25 60.50 20.50 60.63 19.30
9.50 61.25 21.25 61.26 19.50
T 9.75 62.00 22.00 61.89 19.70
10.00 62.50 22.50 62.52 19.90
U 10.50 63.00 23.00 63.15 20.10
10.50 64.00 24.00 63.77 20.30
V 10.75 64.25 24.25 64.40 20.50
11.00 65.00 25.00 65.03 20.70
W 11.25 65.50 25.50 65.66 20.90
11.50 66.50 26.50 66.29 21.10
X 11.75 67.00 27.00 66.92 21.30
12.00 67.50 27.50 67.54 21.50
Y 12.25 68.00 28.00 68.17 21.70
12.50 69.00 29.00 68.80 21.90
Z 12.75 69.50 29.50 69.43 22.10
13.00 70.00 30.00 70.06 22.30

What if I’m planning a surprise gift or proposal?

Ask a close friend or family member

If you are unsure of a person’s ring size, it’s always best to discreetly inquire around you. Close friends or family members may be able to help, or at least give you a good indication of your partner’s ring size.

Measure a ring he or she already owns

It’s important you use a ring usually worn on the finger you are seeking to measure, especially if you are looking for an engagement ring. You’ll get the most accurate size if you take it to our showroom to be measured without them noticing.

However, if you are worried your partner may notice a missing ring, you can also try to measure it at home by using our printable ring size cutout and following the instructions above. Keep in mind any manual method to determine ring size may result in inaccuracies.


  • If you do not know the ring size of the person you are purchasing an engagement ring for, please select “I don’t know” when proceeding with the purchase and we will produce your ring to a standard size.
  • The standard ring size for women is L to M, and for men, Q to S.
  • If you are hesitating between two sizes, the rule is to always aim for the largest as it will be easier to make a ring size smaller than bigger should you make a mistake.
  • Engagement rings are top-heavy due to the weight of the stone. This means a very loose fit may result in the top half of the ring sliding down.

What if I order the wrong ring size?

Making a mistake in your ring size isn’t the end of the world. At 77 Diamonds, we offer a free resizing service for up to 30 days after receiving the item.

Our expert craftsmen will take care in returning your ring both cleaned and polished, ready to fit on your finger.

Keep in mind a certain number of our rings cannot be resized. These include full set diamond eternity rings, milgrain or ornate bands as well as certain bespoke or personalised rings.

If you have bought a ring which cannot be resized, we can exchange your purchase for another ring of similar style within 30 days of receiving the ring. Should you choose a new ring containing more gemstones or diamonds, you may be required to meet the price difference.


What are the average ring sizes for men and women?

The standard ring size for women is L to M, and for men, Q to S.

How tight should a ring be?

We suggest your ring should sit comfortably on the finger without pinching the skin. The ring must be tight enough to not turn on its own, but you should still be able to slide it over your finger with ease. Top-heavy designs, such as engagement rings, are more likely to move on your finger if they are too loose. Also, your fingers tend to swell when it’s warmer, so it’s important you do not choose a size that is too tight.

Can you make a ring bigger if the size is wrong?

Of course! At 77 Diamonds, we offer a complimentary ring resize for up to 30 days after you receive your design. We can add metal to a ring and increase it by a maximum of two sizes. Anything above that will need to be exchanged. Certain full-set or bespoke designs cannot be resized, and will also need to be exchanged for a larger-sized ring.

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