Measure Later in the Day
Finger size can change with temperature and time of day. Measuring later in the day can give a more representative fit.
Size Guide
RING SIZE GUIDE
Sphere Diamond Ring Size Guide
Find your ideal ring size with international sizing references and practical fitting guidance from Sphere Diamond.
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What Is a Ring Size?
Ring size is based on the inner circumference of a ring. Because sizing systems vary by country, a conversion chart helps you compare measurements and choose a comfortable fit.
A well-fitting ring should slide over the knuckle with slight resistance and sit securely at the base of the finger without feeling too tight.
RING SIZE GUIDE
International Ring Size Conversion Chart
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| Inside Circumference | US, Canada, Mexico | France | Germany, Russia, Asia | India, Japan, China | |
|---|---|---|---|---|---|
| IN | MM | ||||
| 1.74 | 44.2 | 3 | 44 | 14 | 4 |
| 1.77 | 44.8 | 3.25 | 45 | 14 1/4 | --- |
| 1.79 | 45.5 | 3.5 | 45.5 | 14 1/2 | 5 |
| 1.82 | 46.1 | 3.75 | 46 | 14 3/4 | 6 |
| 1.84 | 46.8 | 4 | 47 | 15 | 7 |
| 1.87 | 47.4 | 4.25 | 47.5 | --- | --- |
| 1.89 | 48 | 4.5 | 48 | 15 1/4 | 8 |
| 1.92 | 48.7 | 4.75 | 48.5 | 15 1/2 | --- |
| 1.94 | 49.3 | 5 | 49 | 15 3/4 | 9 |
| 1.97 | 50 | 5.25 | 50 | 16 | --- |
| 1.99 | 50.6 | 5.5 | 50.5 | 16 1/4 | 10 |
| 2.02 | 51.2 | 5.75 | 51 | --- | 11 |
| 2.04 | 51.9 | 6 | 52 | 16 1/2 | 12 |
| 2.09 | 53.1 | 6.5 | 53 | 17 | 13 |
| 2.14 | 54.4 | 7 | 54.5 | 17 1/4 | 14 |
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Quick Size Reference
Use the millimeter measurements as a quick reference, then confirm against the full chart before ordering your ring.
US Size 344.2 mm
US Size 3.545.5 mm
US Size 446.8 mm
US Size 4.548 mm
US Size 549.3 mm
US Size 5.550.6 mm
US Size 651.9 mm
US Size 6.553.1 mm
US Size 754.4 mm
US Size 7.555.7 mm
US Size 857 mm
US Size 8.558.3 mm
US Size 959.9 mm
US Size 9.560.8 mm
US Size 1062.1 mm
US Size 10.563.4 mm
US Size 1164.6 mm
US Size 11.565.9 mm
US Size 1267.2 mm
RING SIZE GUIDE
How to Get a More Accurate Fit
Measure More Than Once
Check the measurement two or three times to reduce error, especially when measuring at home.
Consider Band Width
Wider bands can feel tighter than slim bands. If you are unsure, consult Sphere Diamond before confirming the final size.
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Ring Resizing Service
Newly Purchased Items
For newly purchased items resized immediately, completion is usually within 2–3 hours, depending on the design and service queue.
Previously Worn Items
Approximately 10 business days, as the ring is returned to the workshop for structural inspection, stone-security checks and finishing as appropriate.
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Not Sure About Your Ring Size?
Our Sphere Diamond team can help check your ring size and advise on fit for your chosen design at our CentralWorld boutique.
Contact Sphere DiamondSize Guide
Use this guide to find the perfect size for your ring and bracelet. If you need help measuring, our consultants are happy to assist.
Ring Size Chart
Standard international size comparison
| US | UK | Japan | EU | MM |
|---|---|---|---|---|
| 3 | F | 4 | 44 | 44.2 |
| 3.5 | G | 5 | 45 | 45.5 |
| 4 | H | 7 | 47 | 46.8 |
| 4.5 | I | 8 | 48 | 48.0 |
| 5 | J | 9 | 49 | 49.3 |
| 5.5 | K | 10 | 50 | 50.6 |
| 6 | L | 12 | 52 | 51.9 |
| 6.5 | M | 13 | 53 | 53.1 |
| 7 | N | 14 | 54 | 54.4 |
| 7.5 | O | 15 | 55 | 55.7 |
| 8 | P | 16 | 56 | 57.0 |
| 8.5 | Q | 17 | 58 | 58.3 |
| 9 | R | 18 | 59 | 59.5 |
| 9.5 | S | 19 | 60 | 60.8 |
| 10 | T | 20 | 62 | 62.1 |
| 10.5 | U | 21 | 63 | 63.4 |
| 11 | V | 22 | 64 | 64.6 |
| 11.5 | W | 23 | 65 | 65.9 |
| 12 | X | 24 | 67 | 67.2 |
| 12.5 | Y | 25 | 68 | 68.5 |
| 13 | Z | 26 | 69 | 69.7 |
Bracelet Size Chart
Wrist circumference guide
| CM | IN |
|---|---|
| 14 | 5.5 |
| 14.5 | 5.7 |
| 15 | 5.9 |
| 15.5 | 6.1 |
| 16 | 6.3 |
| 16.5 | 6.5 |
| 17 | 6.7 |
| 17.5 | 6.9 |
| 18 | 7.1 |
| 18.5 | 7.3 |
| 19 | 7.5 |
| 19.5 | 7.7 |
| 20 | 7.9 |
