With a smart ring, size matters more than with a normal ring. The sensors on the inside need steady contact with your skin to give you reliable readings, and a ring that fits well is one you will happily wear day and night. This guide shows you how to find your size for the VitalityWatch Glucose Smart Ring at home in about two minutes.
Why the right size matters for a smart ring
- Accuracy: a snug, secure fit keeps the sensors in contact with your finger. Fit has a bigger effect on accuracy than which finger you choose.
- Less rotation: the ring measures best with the two small bumps on the underside of your finger. A well-fitting ring stays in place and doesn't turn more than about 30 degrees.
- Comfort: you will wear the ring 24/7, including while you sleep, so it should feel comfortable, not tight.
What you need
- A thin piece of string or a strip of paper, about 15 cm (6 inches) long
- A pen
- A ruler with millimeters
How to measure your ring size in 4 steps
- Wrap it around your finger. Wrap the string or paper around the base of the finger you want to wear the ring on. It should be snug but not tight.
- Mark the overlap. Use the pen to mark where the string or paper first overlaps.
- Measure the length. Lay it flat and measure from the end to your mark in millimeters. This is your finger circumference.
- Find your size in the chart below.
Glucose Smart Ring size chart
| Finger circumference | Ring size |
|---|---|
| 51.8 mm | 6 |
| 54.7 mm | 7 |
| 57.2 mm | 8 |
| 59.7 mm | 9 |
| 62.6 mm | 10 |
| 65.0 mm | 11 |
| 67.5 mm | 12 |
| 70.1 mm | 13 |
Between two sizes? Choose the larger size for a more comfortable fit.
Tips for the perfect fit
- Measure at the end of the day. Fingers are often slightly larger in the evening and when it is warm.
- Measure the exact finger you will wear it on. Fingers on the same hand can differ by a full size.
- Check that it slides over your knuckle. The ring should go over the knuckle with a little resistance and sit snugly at the base.
- Measure twice. A second measurement takes a minute and avoids ordering the wrong size.
Which finger should I wear my smart ring on?
The best fingers for accurate detection are your index, middle or ring finger, on either hand. Wearing the ring on any of these three fingers gives very consistent results, so pick the one that feels most comfortable and measure that finger.
Frequently asked questions
What sizes does the Glucose Smart Ring come in?
Sizes 6 to 13, from 51.8 mm to 70.1 mm finger circumference, in Midnight Black, Silver White and Glorious Gold.
Should a smart ring be tight?
Snug, not tight. It should stay in place without turning freely, and still feel comfortable when you sleep.
Can I use my normal ring size?
Only if you know it in millimeters of circumference. Ring sizes differ between countries and brands, so measuring with the chart above is the safest way.
Please note: we do not offer exchanges, returns or refunds for incorrect sizes, so take a moment to measure carefully before you order.
Found your size? Choose your color on the Glucose Smart Ring page, or read how the Glucose Smart Ring works first.