Ring Size Guide
Finding your perfect fit is easy. Our rings are listed in US sizes — use the chart below to convert from UK, EU or Japanese sizing, or to measure your size at home.
How to find your ring size at home
1. Measure a ring you already own. Take a ring that fits the intended finger and measure the inside diameter (edge to edge) in millimetres. Match it to the “Inside diameter” table below.
2. Use string or paper. Wrap a thin strip of paper or string snugly around the base of your finger, mark where it overlaps, then measure the length in millimetres — this is your circumference (the EU size). Find it in the conversion table below.
3. Print a ring sizer. If you print a sizer strip, check the scale measures 2 inches so the sizing is accurate.
International ring size conversion
| US & Canada | UK & AUS | EU | Japan |
|---|---|---|---|
| 3 | F | 44 | 4 |
| 3½ | G½ | 45¼ | 5½ |
| 4 | H½ | 46½ | 7 |
| 4½ | I½ | 47¾ | 8 |
| 5 | J½ | 49 | 9 |
| 5½ | L | 50¼ | 10 |
| 6 | M | 51½ | 11 |
| 6½ | N | 52¾ | 13 |
| 7 | O | 54 | 14 |
| 7½ | P | 55½ | 15 |
| 8 | Q | 57 | 16 |
| 8½ | Q¾ | 58 | 17 |
| 9 | R¾ | 59½ | 18 |
| 9½ | S¾ | 61 | 19 |
| 10 | T½ | 62 | 20 |
| 10½ | U½ | 63 | 22 |
| 11 | V½ | 64½ | 23 |
| 11½ | W¾ | 66 | 24 |
| 12 | Y | 67 | 25 |
Inside diameter by size
| US Size | Inside diameter (mm) | Inside diameter (in) |
|---|---|---|
| 3 | 14.1 mm | 0.55 in |
| 4 | 14.9 mm | 0.59 in |
| 5 | 15.7 mm | 0.62 in |
| 6 | 16.5 mm | 0.65 in |
| 7 | 17.3 mm | 0.68 in |
| 8 | 18.1 mm | 0.71 in |
| 9 | 19.0 mm | 0.75 in |
| 10 | 19.8 mm | 0.78 in |
| 11 | 20.6 mm | 0.84 in |
| 12 | 21.4 mm | 0.87 in |
| 13 | 22.2 mm | 0.91 in |
| 14 | 23.0 mm | 0.94 in |
Sizing tips
- Measure at the end of the day, when fingers are at their largest.
- Make sure the ring can pass comfortably over your knuckle.
- Avoid measuring when your hands are cold — fingers shrink.
- If you’re between sizes, size up for comfort.
- Wider bands fit more snugly — consider going up half a size.
Ring sizing FAQs
Which size scale do you use?
All Senior & Co rings are listed in US sizes. Use the conversion table above to find your equivalent UK, EU or Japanese size.
What if I’m between sizes?
We recommend choosing the larger size, especially for wider bands.
Can I exchange if the size isn’t right?
Yes — we offer hassle-free returns within 30 days. Send back any unworn item in its original packaging and we’ll sort an exchange.
How accurate is measuring at home?
Home methods are a great guide. For total certainty, pop into any jeweller for a professional sizing.