Home / Ring size guide
Ring size guide
Last updated 27 October 2026
The quick answer: measure the inside diameter of a ring that already fits the same finger, or wrap a strip of paper around the finger and measure its length. Then match the number to the chart below. For a wide spinner or fidget ring, if you're between sizes, choose the larger size.
How to measure your ring size at home
Method 1: Use a ring that already fits (most accurate)
- Choose a ring that fits the finger you'll wear the new ring on.
- Lay it flat on a ruler and measure straight across the inside edge, in millimetres.
- Find the closest inside diameter in the chart below.
Method 2: Paper strip or string
- Cut a thin strip of paper, about 5 mm wide (string stretches, so paper is better).
- Wrap it snugly around the base of your finger. It should slide over your knuckle with a little resistance.
- Mark where the paper overlaps, lay it flat and measure the length in millimetres. This is your circumference.
- Find the closest circumference in the chart. Measure two or three times to be sure.
Tips for an accurate measurement
- Measure at the end of the day, when your hands are warm. Fingers are smaller in the morning and in the cold.
- If your knuckle is larger than the base of your finger, choose a size that will fit over the knuckle.
- Your dominant hand is usually slightly larger, by up to half a size.
Ring size chart: US, Australia and UK
Australia and the UK use the same letter sizes. Canada uses US sizes. Our rings are listed in US sizes.
| US / Canada | Australia / UK | Inside diameter | Inside circumference |
|---|---|---|---|
| 4 | H½ | 14.9 mm | 46.8 mm |
| 5 | J½ | 15.7 mm | 49.3 mm |
| 6 | L½ | 16.5 mm | 51.9 mm |
| 7 | N½ | 17.3 mm | 54.4 mm |
| 8 | P½ | 18.1 mm | 57.0 mm |
| 9 | R½ | 19.0 mm | 59.5 mm |
| 10 | T½ | 19.8 mm | 62.1 mm |
| 11 | V½ | 20.6 mm | 64.6 mm |
| 12 | X½ | 21.4 mm | 67.2 mm |
| 13 | Z½ | 22.2 mm | 69.7 mm |
Each half US size adds about 0.4 mm to the diameter (about 1.3 mm to the circumference). Charts from different jewellers can differ by up to half a size, so when you're unsure, contact us before ordering.
Sizing a spinner or fidget ring
Our spinner and fidget rings range from dainty 2 mm bands to bold 8 mm and wider styles. The band width is listed in each product description. A wide band sits against more of your finger, so it feels tighter than a thin ring in the same size.
- Band under 4 mm: order your usual size.
- Band 4–6 mm: order your usual size, or half a size up if you're between sizes.
- Band over 6 mm: consider half a size to a full size up, especially if you normally wear thin rings.
A ring that's slightly loose still spins well. One that's too tight is uncomfortable and harder to spin, so if in doubt, go up.
Which sizes we make
- Spinner and fidget rings: US 5–13
- Cross and faith rings: US 5–13, with half sizes on some designs
- Memorial and fine rings: US 4–10
The available sizes for each design are listed on its product page.
Still not sure?
Email spinringstudio@gmail.com before you order, with your measurement and the ring you're looking at, and we'll help you confirm your size. If it doesn't fit, size exchanges are accepted within 30 days of delivery, as set out in our shipping and returns policy.
Common questions
Should I size up for a spinner ring?
For wide styles, often yes. A band of about 6 mm or more feels tighter than a thin ring in the same size. If your measurement falls between two sizes, or you normally wear thin rings, choose half a size to a full size larger. Thin spinner rings (under 4 mm) can be ordered in your usual size.
What is a US size 7 ring in Australian sizes?
A US size 7 is about N½ in Australian and UK sizes, with an inside diameter of about 17.3 mm and an inside circumference of about 54.4 mm.
What time of day should I measure my ring size?
Measure at the end of the day when your hands are warm. Fingers are smaller in the morning and in cold weather, so a measurement taken then can come out too small.
What if I don't know my ring size when I order?
Email us before you order and we'll help you confirm your size. Size exchanges are accepted within 30 days of delivery.
Spinner rings · Cross jewellery · Memorial rings · Shipping & Returns · spinringstudio@gmail.com
Calm Jewelry is a trading name of MACARIUS AUSTRALIA · ABN 54 513 897 466 · Victoria, Australia