Find Your Perfect Fit
A guide to accurate ring sizing and diamond proportions.
1. Ring Size Conversion Chart
We use the standard Australian/UK (Alphabetical) sizing system. Use the table below to find your match based on your diameter or circumference.
| Inside Diameter (mm) | Inside Circumference (mm) | AU / UK Size | US / Canada Size |
|---|---|---|---|
| 14.1 mm | 44.2 mm | F | 3 |
| 14.9 mm | 46.8 mm | H | 4 |
| 15.7 mm | 49.3 mm | J ½ | 5 |
| 16.5 mm | 51.9 mm | L ½ | 6 |
| 17.3 mm | 54.4 mm | N ½ | 7 |
| 18.1 mm | 57.0 mm | P ½ | 8 |
| 18.9 mm | 59.5 mm | R ½ | 9 |
Includes printable ruler and physical sizing circles.
2. Stone Size: mm vs. Carat Weight
Diamond carat weight measures mass, while millimeter (mm) measures physical dimensions. Use this as a visual reference for Round Brilliant cut stones.
| Carat Weight (ct) | Round Diameter (mm) | Style Guide |
|---|---|---|
| 0.25 ct | 4.1 mm | Subtle & Minimalist |
| 0.50 ct | 5.2 mm | The Classic Choice |
| 1.00 ct | 6.5 mm | Timeless Brilliance |
| 1.50 ct | 7.4 mm | Commanding Presence |
| 2.00 ct | 8.1 mm | Luxury Statement |
Professional Measurement Tips
Temperature: Fingers shrink in the cold and swell in the heat. Measure at the end of the day when your hands are warm.
Band Width: Wider bands feel tighter on the finger. If you are choosing a wide eternity band, we recommend ordering one half-size larger.
Between Sizes: If you fall between two sizes, always opt for the larger size to ensure a comfortable fit.