Size guide

With a ring, the right size matters more than anything else: a ring that fits well is comfortable to wear and gives more accurate readings.

How to measure your finger

Measure in the evening — fingers swell slightly during the day, so an evening measurement is the most reliable. Avoid measuring right after exercise or when your hands are very cold.
Cut a strip of paper about 1 cm wide and 10 cm long. Wrap it around your finger where the ring will sit — snug, but not tight.
Mark the point where the end of the paper overlaps, then measure the length in millimetres with a ruler. This is your finger’s circumference.
Compare the result with the table below. Make sure the ring will also slide over your knuckle.

If you’re between two sizes, choose the larger one. A ring that is too tight feels uncomfortable, while a slightly roomier one sits better day to day.

Size	Finger circumference	Inner diameter
8	57.0 mm	18.1 mm
9	59.5 mm	18.9 mm
10	62.1 mm	19.8 mm
11	64.6 mm	20.6 mm
12	67.2 mm	21.4 mm
13	69.7 mm	22.2 mm

Which finger?

We recommend wearing WYRA on your index finger — the ring usually fits best there and stays in place overnight. The middle finger works well too. Be sure to measure the finger you actually plan to wear it on, as finger sizes vary.

Still have questions? See our frequently asked questions or get in touch.