February 11, 2019

There is a lot of information, tips and stories about ring sizing out there. We have sifted through it all to provide you with some simple ring education. Read our guide on how engagement ring sizing works and how to choose the correct size for you or your partner.

Understanding ring sizes

Here at Louise Jean, our rings are made to US ring sizes which are based on a numerical scale from 3 - 15. These numbers correlate with the circumference of the inside of a band, measured in millimetres. The difference from one ring size to the next is a matter of 2 - 3mm in the circumference of the inner part of the band, where it touches the finger. The difference between a ring that fits and one that doesn’t could be just 1mm. In Australia, our ring sizes are based on an alphabetical scale (technically termed Wheat Sheaf). At Louise Jean, you will find the US size and the Australian sizing equivalent on all of our rings. Use this simple ring size guide if you already know your size and need to convert it to another scale.


The ring finger

Engagement rings and wedding bands are traditionally worn on the left ring finger (the one next to the pinky). Usually, the dominant hand’s ring finger (the hand you write with) is ½ a size larger than the non-dominant hand. This is important to note as most people don’t know what their left-hand ring finger size is but many know the size or wear jewellery on their right-hand ring finger.

What is their ring size?

The average female ring finger is a size 6, for a ring that is about 2 - 3mm wide and a for a male the average ring size is an 8, and that’s for a ring that is about 4 - 6mm wide. At Louise Jean most of our ready to ship and one of a kind, rings are a size 6, and our bands are all about 2 - 3mm wide except for our custom-made pieces. That being said, it’s not uncommon to be smaller or larger than a size 6, but almost all engagement ring orders fall in the range of 5 - 8. If you know their size is somewhere between a 6 and a 6.5, always stay with the larger size, it is much easier to make adjustments down in size. Making changes after the fact is totally normal and something that can be easily arranged for you through Louise Jean.

Strategies for Figuring Out their Ring Size

If you have missed all the hints and still don’t know the perfect ring size, don’t worry we have a few tried and tested techniques that will save you some stress.
  • Pick a ring that can be resized, and let Louise Jean know that you’ll likely need to do that.
  • Ask a close friend or family member.
  • Try borrowing a ring that fits their ring finger of their right hand, measure the internal diameter with a transparent ruler or trace the inside of the ring onto a piece of paper. Bring this into Louise Jean or your local jeweller, and we can try to match it with one of our official ring sizing bands. Or measure the diameter in millimetres and use this chart.


All Ceremonial Rings are made to order and are prepared to any size requirements. Please specify your exact size in the notes section upon checkout, or you can email us with your order number and size. Custom sizing is only available for Ceremonial/made to order pieces. 

The most accurate way to determine your ring size is to go to a trusted jewellery store and have them measure your finger for you. We do offer one complimentary size adjustment; however, the customer is responsible for any associated shipping costs. Alternatively, you can obtain a free ring sizer from us- shipping rates are calculated at checkout. 

Circumference (mm) Inside Diameter (mm) Australia, United Kingdom & New Zealand The United States & Canada
44.2 14.1 F 3
44.8 14.3
45.5 14.5 G
46.1 14.7
46.8 14.9 H 4
47.4 15.1
48 15.3 I
48.7 15.5 J
49.3 15.7 5
50 15.9 K
50.6 16.1
51.2 16.3 L
51.9 16.5 6
52.5 16.7 M
53.1 16.9
53.8 17.1 N
54.4 17.3 7
55.1 17.5 O
55.7 17.7
56.3 17.9 P
57 18.1 8
57.6 18.3 Q
58.3 18.5
58.9 18.8 R
59.5 19.0 9
60.2 19.2 S
60.8 19.4
61.4 19.6 T
62.1 19.8 10
62.7 20.0 U 10¼
63.4 20.2 10½
64 20.4 V 10¾
64.6 20.6 11
65.3 20.8 W 11¼
65.9 21.0 11½
66.6 21.2 X 11¾
67.2 21.4 12
67.8 21.6 Y 12¼
68.5 21.8 Z 12½