Mazzucchelli's Ring Size Guide
Find Your Perfect Ring Size
Choosing the right size is simple with our at-home methods, printable guide, and in-store sizing options. Whether you’re buying for yourself or someone special, our tools help you find the perfect fit in AU letters and US numbers.
Quick Ring Size Finder
Measure the inside diameter of a ring you already wear or the circumference of your finger. Use the chart below to find the nearest Australian and US size.
- Inside Diameter Example
- 17.5 mm = AU O / US 7.25
- Finger Circumference Example
- 52.4 mm = AU M / US 6.25
Use our Printable Ring Sizer for an easy at-home option.
How to Measure your Ring Size at Home
Method 1 - Measure a Ring
- Choose a ring that fits the intended finger.
- Measure the inner diameter in millimetres.
- Match it to our chart below.
Method 2 — Measure Your Finger
- Wrap a thin strip of paper around the base of your finger.
- Mark where the paper overlaps.
- Measure the length in millimetres (circumference).
- Use the chart to find your AU and US size.
Pro Tips
- Measure in the afternoon or end of the day when your hands are warm.
- If between ring sizes, choose the larger or nearest half size.
- Wide bands (5 mm+) usually fit tighter, go up half a size.
- Always measure the exact finger the ring will be worn on.
- For engagement rings, visit us in-store for professional sizing.
AU ↔ US Ring Size Chart
| AU (Letter) | US | Inside Diameter (mm) | Finger Circumference (mm) |
|---|---|---|---|
| G | 3.5 | 14.5 | 45.5 |
| G½ | 3.8 | 14.7 | 46.1 |
| H | 4.0 | 14.9 | 46.7 |
| H½ | 4.3 | 15.1 | 47.4 |
| I | 4.5 | 15.3 | 48.0 |
| I½ | 4.8 | 15.5 | 48.7 |
| J | 5.0 | 15.7 | 49.3 |
| J½ | 5.3 | 15.9 | 49.9 |
| K | 5.5 | 16.1 | 50.6 |
| K½ | 5.8 | 16.3 | 51.2 |
| L | 6.0 | 16.5 | 51.8 |
| L½ | 6.3 | 16.7 | 52.5 |
| M | 6.5 | 16.9 | 53.1 |
| M½ | 6.8 | 17.1 | 53.8 |
| N | 7.0 | 17.3 | 54.4 |
| N½ | 7.3 | 17.5 | 55.0 |
| O | 7.5 | 17.7 | 55.7 |
| O½ | 7.8 | 17.9 | 56.3 |
| P | 8.0 | 18.1 | 56.9 |
| P½ | 8.3 | 18.3 | 57.6 |
| Q | 8.5 | 18.5 | 58.2 |
| Q½ | 8.8 | 18.7 | 58.9 |
| R | 9.0 | 18.9 | 59.5 |
| R½ | 9.3 | 19.2 | 60.1 |
| S | 9.5 | 19.4 | 60.8 |
| S½ | 9.8 | 19.6 | 61.4 |
| T | 10.0 | 19.8 | 62.1 |
| T½ | 10.3 | 20.0 | 62.7 |
| U | 10.5 | 20.2 | 63.4 |
| U½ | 10.8 | 20.4 | 64.0 |
| V | 11.0 | 20.6 | 64.6 |
| V½ | 11.3 | 20.8 | 65.2 |
| W | 11.5 | 21.0 | 65.9 |
| W½ | 11.8 | 21.2 | 66.5 |
| X | 12.0 | 21.4 | 67.2 |
| X½ | 12.3 | 21.6 | 67.8 |
| Y | 12.5 | 21.8 | 68.4 |
| Y½ | 12.8 | 22.0 | 69.1 |
| Z | 13.0 | 22.2 | 69.7 |
| Z1 | 13.3 | 22.4 | 70.3 |
| Z2 | 13.7 | 22.8 | 71.6 |
| Z3 | 14.0 | 23.0 | 72.3 |
Frequently Asked Questions
It should pass over your knuckle with slight resistance and sit comfortably without spinning. If in doubt, go up half a size.
No. AU/UK use letters, US/CA use numbers, and EU uses inner circumference (mm). Always refer to our chart for conversions.
Most gold and sterling silver rings can be resized. Titanium, tungsten, and full-eternity designs usually cannot. Ask our jewellers before resizing.
At-home methods are accurate for most rings, but in-store professional sizing is always best, especially for engagement rings and wider bands.
Download the Printable Ring Size Guide or visit a Mazzucchelli’s store near you for expert help in finding the perfect fit.
