Size Guide
Get this right and everything else is easy.
Sizing is the single biggest reason people exchange a smart ring. Five minutes now saves you a fortnight of shipping later.
The paper strip method
- Cut a thin strip of paper, about 4 inches long.
- Wrap it snugly around the base of the finger you'll wear the ring on — snug, not tight enough to pinch.
- Mark where the end overlaps, then lay the strip flat and measure to the mark in millimeters.
- Match that circumference to the chart below.
Size chart
| US size | Inner circumference | Inner diameter |
|---|---|---|
| US 6 | 51.9 mm | 16.5 mm |
| US 7 | 54.4 mm | 17.3 mm |
| US 8 | 57.0 mm | 18.1 mm |
| US 9 | 59.5 mm | 19.0 mm |
| US 10 | 62.1 mm | 19.8 mm |
| US 11 | 64.6 mm | 20.6 mm |
| US 12 | 67.2 mm | 21.4 mm |
Four things that trip people up
- Measure late in the day. Fingers swell as the day goes on. A morning measurement will give you a ring that's tight by evening.
- Don't measure when you're cold. Cold fingers are noticeably smaller. Warm up first.
- A smart ring sits differently than jewelry. It needs consistent skin contact to read properly, so err slightly snug rather than loose — but you should still be able to slide it off without a struggle.
- Measure the finger you'll actually wear it on. Your index and ring fingers are rarely the same size.
Between two sizes?
Go with the larger one. A slightly loose ring is uncomfortable to nobody; a tight one is unwearable. And if it turns out wrong, email us — exchanges are straightforward.