RING SIZE HELP
Measure Your Ring SIze
We’re here to make the process of measuring your ring size as simple and as accurate as possible to help you find your ideal fit. We've covered everything you need to know about ring sizing below.
If you require personalised assistance please reach out to our expert team.
How To Measure Your Ring Size:
For the most accurate measurement, we recommend using a ring sizer, which you can purchase here
- Slide the ring sizer onto your finger and adjust it until it fits comfortably. Make sure it's not too tight or too loose.
- If you have a ring that already fits well, place it over the circles on our chart to find your size. Make sure the inside edge of the ring lines up with the outside edge of the circle.
- Wrap a string or strip of paper around the base of your finger, mark the point where it overlaps, then measure the length against a ruler. Use our ring size chart to find your size based on this measurement.
To ensure a perfect fit, keep the following tips in mind:
- Measure your finger at the end of the day when it's at its largest.
- A perfectly fit ring should slide over your knuckle with some friction and then sit comfortably snug on your finger.
- Avoid measuring your fingers when they are cold, as they may be smaller than usual.
- Consider the width of the ring. Wider rings usually require a slightly larger size for comfort.
- If you're between sizes, it's usually best to choose the larger size.
Planning to surprise someone with a ring?
Here are a few tips to help you find their size without them knowing:
- Ask a Friend or Family Member: They may know the recipient's ring size or can help you find out subtly.
- Borrow a Ring: If the recipient already wears rings, borrow one that fits well and use our size chart to determine its size.
- Measure in Secret: If you can access a ring the recipient wears, trace the inside on a piece of paper and use our chart to estimate the size."
These ring size guides are a simple way to measure and determine your exact alphabetical ring size. Simply wrap around your chosen finger, slide the end through and tighten to your desired fit.
Understanding Ring Sizes
Ring Size Conversion Chart
Ring sizes can differ significantly across countries and regions, which can make choosing the right size a bit confusing. In the UK, ring sizes are measured alphabetically, while in the US, they are measured numerically. Knowing your size in the system used by the jeweller is essential for getting the perfect fit. We recommend using the below conversion chart to help you convert between different sizing systems and understand how ring sizes are determined.
Extra Small: F – G; Small: H – J; Small/Medium: K – L; Medium: M – O; Medium/Large: P – Q; Large: R – T; Extra Large: U+
Circumference (mm) |
Inside Diameter (mm) |
Australia, UK & Europe |
United States & Canada |
China, Japan & Singapore |
44.2 | 14.1 | F | 3 | 4 |
45.5 | 14.5 | G | 3 1/2 | 5 1/2 |
46.8 | 14.9 | H | 4 | 7 |
48.0 | 15.3 | I | 4 1/2 | 8 |
48.7 | 15.5 | J | 4 3/4 | 8 1/2 |
50.0 | 15.9 | K | 5 1/4 | 9 1/2 |
51.2 | 16.3 | L | 5 3/4 | 10 1/2 |
52.5 | 16.7 | M | 6 1/4 | 12 |
53.8 | 17.1 | N | 6 3/4 | 13 1/2 |
55.1 | 17.5 | O | 7 1/4 | 14 1/2 |
56.3 | 17.9 | P | 7 3/4 | 15 1/2 |
57.6 | 18.3 | Q | 8 1/4 | 16 1/2 |
58.9 | 18.8 | R | 8 3/4 | 17 1/2 |
60.2 | 19.2 | S | 9 1/4 | 18 1/2 |
61.4 | 19.6 | T | 9 3/4 | 19 1/2 |
62.7 | 20.0 | U | 10 1/4 | 21 |
64.0 | 20.4 | V | 10 3/4 | 22 1/2 |
65.3 | 20.8 | W | 11 1/4 | 23 1/2 |
66.6 | 21.2 | X | 11 3/4 | 24 1/2 |
67.8 | 21.6 | Y | 12 1/4 | 25 1/2 |
68.5 | 21.8 | Z | 12 1/2 | 26 |
70.4 | 22.4 | Z+1 | 13 1/4 | 27 1/2 |
Ring Size Adjustments
Don't worry if the ring isn't a perfect fit when it arrives. The One Diamond Atelier offers ring resizing services for most rings, ensuring that you or your loved one will have the perfect fit. Please note that not all rings can be resized, if you are unsure, please reach out to our team for assistance.
The above Ring Size Guides are intended as a guideline only. Ring sizes may vary depending on the style of the ring, or the shape of your finger and personal preferences on fit. We recommend having your ring size professionally measured ahead of placing an online order. You can visit a local jeweller within your city to determine your ideal ring size. This will allow you to order from The One Diamond Atelier with confidence in your selected ring size.
We're here to help
Please contact us personalized assistance