Smart Ring Size Guide
How to find your size
- Use a ring that fits. Measure its inside edge to edge in millimeters and match it to the inner diameter below.
- Or wrap a paper strip around the base of your finger, mark where it overlaps, and match the length to the circumference below.
- Between two sizes? Choose the larger one. Smart rings are thicker than regular bands, so they fit more snugly.
Measure the finger you plan to wear the ring on, ideally at the end of the day when fingers are slightly larger.
US sizes and inner diameters
| US size | Inner diameter | Circumference |
|---|---|---|
| 7 | 17.3 mm | 54.4 mm |
| 8 | 18.2 mm | 57.2 mm |
| 9 | 19.0 mm | 59.7 mm |
| 10 | 19.9 mm | 62.5 mm |
| 11 | 20.7 mm | 65.0 mm |
| 12 | 21.5 mm | 67.5 mm |
| 13 | 22.2 mm | 69.7 mm |
Available sizes vary by model, and some models list their exact inner diameters under Specifications on the product page.
Need a different size?
Size exchanges are available. Please contact support@bkwat.com before sending anything back. Shipping costs for an exchange are paid by the customer. See our Return and Refund Policy for details.