Ring Size Guide
Whether you're sizing your own finger or planning a surprise, getting it right the first time means less waiting and more wearing. Here's how to find your size in minutes, plus our full conversion chart.
How to Measure Your Size
Two simple ways to get an accurate measurement at home, using a ring you already own or a strip of paper.
Inside Diameter
Take a ring that already fits the finger you're sizing for. Measure the inner width edge-to-edge in millimetres, then match it against the Inside Diameter column in the chart below.
Circumference
Wrap a thin strip of paper or string snugly around the base of the finger, mark where it meets, then measure that length in millimetres. Match it to the Circumference column below.
Size Conversion Chart
US/Canada sizing alongside inside diameter, circumference, and the equivalent EU/ISO size.
| US / Canada | Inside Diameter (mm) | Circumference (mm) | EU / ISO Size |
|---|---|---|---|
| 0.5 | 12.0 mm | 37.8 mm | 38 |
| 1.0 | 12.4 mm | 39.1 mm | 39 |
| 1.5 | 12.8 mm | 40.4 mm | 40 |
| 2.0 | 13.2 mm | 41.6 mm | 42 |
| 2.5 | 13.6 mm | 42.9 mm | 43 |
| 3.0 | 14.1 mm | 44.2 mm | 44 |
| 3.5 | 14.5 mm | 45.5 mm | 45 |
| 4.0 | 14.9 mm | 46.8 mm | 47 |
| 4.5 | 15.3 mm | 48.0 mm | 48 |
| 5.0 | 15.7 mm | 49.3 mm | 49 |
| 5.5 | 16.1 mm | 50.6 mm | 51 |
| 6.0 | 16.5 mm | 51.9 mm | 52 |
| 6.5 | 16.9 mm | 53.1 mm | 53 |
| 7.0 | 17.3 mm | 54.4 mm | 54 |
| Sizes 7.5–8.0 to be added | |||
| 8.5 | 18.5 mm | 58.3 mm | 58 |
| 9.0 | 19.0 mm | 59.5 mm | 60 |
| 9.5 | 19.4 mm | 60.8 mm | 61 |
| 10.0 | 19.8 mm | 62.1 mm | 62 |
| 10.5 | 20.2 mm | 63.4 mm | 63 |
| 11.0 | 20.6 mm | 64.6 mm | 65 |
| 11.5 | 21.0 mm | 65.9 mm | 66 |
| 12.0 | 21.4 mm | 67.2 mm | 67 |
| 12.5 | 21.8 mm | 68.5 mm | 69 |
| 13.0 | 22.2 mm | 69.7 mm | 70 |
| 13.5 | 22.6 mm | 71.0 mm | 71 |
| 14.0 | 23.0 mm | 72.3 mm | 72 |
| 14.5 | 23.4 mm | 73.5 mm | 74 |
| 15.0 | 23.8 mm | 74.8 mm | 75 |
Measurements are approximate. For an exact fit, we recommend confirming your size in-store or with a free ring sizer.
Expert Fitting Advice
A couple of adjustments our jewellers always check for before a ring goes into production.
The Half-Size Rule
Landed between two sizes? Choose the larger one. A slightly looser fit is more comfortable day-to-day than a band that's tight.
Wide Band Adjustment
Bands wider than 6mm sit more snugly than thin bands. If your ring has a wide band, size up by half a size from your usual measurement.
Sizing Secretly? Two More Options
Planning a surprise means you can't always ask directly. These work well without giving anything away.
Trace a Ring They Already Wear
Borrow a ring from the correct finger while they're distracted. Trace both the inner and outer edge onto paper, then measure the inner circle against the chart above. Do this with a couple of their rings if you can, to double-check.
Ask Someone Close to Them
A parent or close friend can often give a good estimate, especially if you have them casually try a few affordable rings for size. Bring what you learn into a Kerose store and our jewellers will help you narrow it down precisely.
Still not sure of your size?
Our jewellery experts can help you get it right before you order.