A smart ring buying guide starts with one idea: the price on the box is only part of what you pay. A smart ring is a small band worn on one finger. It tracks sleep, heart rate and skin temperature while you wear it day and night. Compare four things before you buy: fit, battery, ongoing fees and what you can do with your data.
Start with fit, because the ring is worn all day
A ring that spins or pinches will end up in a drawer. Fit also affects the readings, because the sensors need steady contact with your skin.
Both main makers sell sizing kits for this reason. A sizing kit is a set of plain sample rings in each size. You wear one for a day or so, then order your size. Oura gave a free sizing kit with a Gen3 purchase, according to iMore's January 2022 review. Ultrahuman ships a free kit with plastic sizers from size 6 to 12 and says its sizes differ a little from standard US ring sizes. It does not offer half sizes.
Try the kit on the finger you plan to wear the ring on. Fingers swell in heat and after exercise, so test at different times of day.
Sources: iMore, "Oura Ring Gen 3 review" (imore.com, January 2022); Ultrahuman Ring AIR product page, FAQ section (ultrahuman.com, archived October 26, 2023).
Check battery claims against real use
Battery life is the next thing to compare. A ring is small, so the battery is tiny, and makers quote the best case.
Ultrahuman lists up to 6 days on a full charge for its Ring AIR and 1.5 to 2 hours to charge from empty. Its listed weight is 2.4 to 3.6 grams, depending on size. Reviewers of the Oura Gen3 reported about 4 to 5 days between charges in daily use. They noted that the older Gen2 lasted 6 to 7 days.
Plan for the lower number. A ring that dies every fifth day is easy to forget on the charger. Pick a charging habit you can keep, such as every few days while you shower.
Sources: Ultrahuman Ring AIR product page, technical specifications (ultrahuman.com, archived October 26, 2023); iMore, "Oura Ring Gen 3 review" (imore.com, January 2022).
Add up the membership fee
This is where the two makers differ most. The Oura Gen3 sold from $299 for the silver and black finishes and $399 for stealth and gold. It also needs a membership, which cost $5.99 a month in early 2022. At that rate, a year of membership adds about $72 to the ring price.
The iMore review said that without the membership you keep the basics in the app, while advanced features and data are locked. It also said new buyers then got six months of membership free. Trial offers change, so check what the maker offers today before you order.
Ultrahuman launched its Ring AIR in June 2023 at $349. Its FAQ says there are no recurring fees to see your data, and that one purchase gives lasting access to the ring and your data. Extras cost more: engraving is $39 and a damage and loss plan, UltrahumanX, was $30 a year.
A simple test helps. Add the ring price to two years of fees. Then compare totals, not sticker prices.
Sources: iMore, "Oura Ring Gen 3 review" (imore.com, January 2022); T3, "Oura, beware! Ultrahuman launches lightest smart ring on the market" (t3.com, June 20, 2023); Ultrahuman Ring AIR product page, FAQ and add-ons (ultrahuman.com, archived October 26, 2023).
Ask what happens to your data
A smart ring collects a steady stream of body data. Before you buy, find out where it goes and whether you can keep it.
Check three things on the maker's site. First, does the app work with Apple Health or Google Fit? iMore reported that the Oura app syncs with both. Second, what do you lose if you stop paying for a membership? Third, can you export your own records, and in what format? Makers rarely lead with the third answer, so look for it in the help pages or ask support in writing.
Also read the privacy policy for who can see your data and whether it is sold or shared. If an answer is vague, treat that as an answer.
Sources: iMore, "Oura Ring Gen 3 review" (imore.com, January 2022); Ultrahuman Ring AIR product page, FAQ (ultrahuman.com, archived October 26, 2023).
A short checklist before you order
- Order the sizing kit first and wear it for a day or two.
- Use the lower battery estimate, not the box claim.
- Add the ring price to two years of fees.
- Check delivery time. Ultrahuman listed four to six weeks for the Ring AIR in October 2023.
- Look for trade-in credit if you own an older ring. Ultrahuman listed $50 for an Oura Gen3 at that time.
- Confirm how you can get your data out before you start wearing it.
A smart ring is a wellness gadget, not a medical device. Use it to notice your own trends, and talk to a clinician about health questions.
Sources: Ultrahuman Ring AIR product page (ultrahuman.com, archived October 26, 2023).