Frequently asked questions

Of the rings we cover, the RingConn Gen 3, Gen 2 and Gen 2 Air, the Samsung Galaxy Ring and the Ultrahuman Ring PRO charge no required fee, and Circular says the Circular Ring 2 has “no forced subscription.” Ultrahuman sells optional add-ons, and Circular plans paid “Circular Coins” for some future features. Oura is the exception: its full features need a paid membership. Our ranked list is the best smart rings without a subscription.

Oura lists it at $5.99 a month or $69.99 a year in the US (checked Sep 19, 2026). On the annual plan that's $209.97 over three years and $349.95 over five, on top of the ring. Without it, the app shows only the three daily scores (Readiness, Activity and Sleep), the ring's battery, your profile, settings and Explore content. The full math is in what the Oura membership costs.

No. We haven't lab-tested these rings; every pick is labeled Researched, meaning it was scored from the brand's published fee policy, specs, sizing and warranty terms and from published validation studies. When we mention what a ring did on someone's finger, we name the reviewer who reported it. The full method is on our methodology page.

As an Amazon Associate we earn from qualifying purchases, at no extra cost to you. No brand pays for placement or reviews, and commissions never change a score or the order of a list. Links to Ultrahuman, Circular and WHOOP earn us nothing. Details are on the affiliate disclosure page.

Amazon sets ring prices and changes them often, and we don't have a live, verified price feed connected yet. So every button says “Check price on Amazon” instead of a number that might be stale. When live prices arrive, each will carry an “as of” date and disappear if it isn't refreshed within 48 hours. Subscription fees are shown because they're published brand policy, dated when we checked them.

No official equivalence exists. RingConn says its Gen 3 sizes “differ from other RingConn rings, standard rings and other smart ring brands,” and Oura says its sizes differ slightly from standard US ring sizes and between its own generations. Use the sizing kit for the exact ring you're buying; Oura and RingConn offer theirs free. See smart ring sizing compared.

Oura recommends the index finger for the best accuracy, according to its sizing guide. Other brands publish their own guidance, so follow the one for the ring you buy, and try the sizer on the finger you plan to wear it on. More in which finger to wear a smart ring on.

Maker claims run from 6–9 days for the Oura Ring 5 (“depending on ring size and usage”) to up to 14 days for the RingConn Gen 3 and up to 15 for the Ultrahuman Ring PRO. Reviewers have reported less: DC Rainmaker got 6–7 days from the Oura Ring 5, and The Gadgeteer's reviewer got about 10 days from the RingConn Gen 3 with alerts on. See smart ring battery life.

Oura, Samsung and Circular say their rings are HSA/FSA eligible, and RingConn and Ultrahuman offer it through the checkout partner Flex. But IRS rules exclude expenses that are “merely beneficial to general health,” so Flex runs a telehealth consultation, and a clinician may issue a Letter of Medical Necessity if you have a qualifying condition. Check with your plan administrator before you buy; more in smart ring HSA/FSA eligibility.

No. Samsung supports the Galaxy Ring on Android phones only (Android 11 or later). Even on Android, Double Pinch and Find My Ring don't work on non-Samsung phones, and Energy Score insights need a Samsung Galaxy AI phone. iPhone owners should start with the best smart rings for iPhone.

The Ultrahuman Ring PRO is on US pre-order from Ultrahuman's own store, which says it “ships October 10th onwards”; we found no listing for the ring itself on Amazon.com, only its sizing kit. The older Ring AIR isn't sold in the US after a 2025 US International Trade Commission exclusion order, and a March 2026 US Customs ruling cleared the redesigned Ring PRO. See our Ultrahuman Ring PRO review.

For overnight resting readings, the best evidence is good: in Dial et al. (2025), the Oura Gen 4 had a mean absolute percentage error of 1.94% for resting heart rate and 5.96% for HRV against a Polar H10 chest strap, across 13 adults and 536 nights. That study didn't test workouts or other brands, and DC Rainmaker found the Oura Ring 5's workout heart rate “falls apart” on a trail descent. Evidence for most other rings is thinner; see how accurate smart rings are.

Not today. None of the ring features we cover is FDA-cleared, and we found no smart ring with an FDA-cleared blood pressure feature; Samsung has announced an FDA-cleared sleep apnea risk feature for the Galaxy Ring, due in fall 2026 according to press reports. The FDA has also warned that no smartwatch or smart ring is authorized to measure blood glucose on its own. Treat ring readings as wellness trends, talk to a clinician about symptoms, and see smart rings and sleep apnea and our health content rules.

Wear a chest strap that records beat-to-beat heart rate alongside the ring, and compare the two over the same resting periods. The Polar H10 is a sensible choice because it was the reference device in the Dial et al. study. Our step-by-step method is in test your ring against a chest strap, and the strap options are in the best chest strap for HRV.

For rings, it's the weighted average of six sub-scores: cost of ownership (3 years) (30%), evidence of accuracy (25%), battery (claimed) (15%), sizing & fit (10%), data ownership (10%), platform support (10%). It's an editorial judgment from published fees, specs, studies and warranty terms, not a test result. The rubric and a worked example are on our methodology page.

No. WHOOP sells its band as part of a membership rather than as a one-time purchase, and a WHOOP staff reply on the WHOOP Community forum says that once the membership ends, “WHOOP will no longer collect, upload, or analyze your biometric data.” If you want to avoid a fee, see WHOOP alternatives without a subscription or Oura vs WHOOP.

Fees and rankings are re-checked monthly, comparisons and reviews quarterly, and accuracy, battery and sizing guides every six months, with any page updated sooner if a brand changes a fee, a model launches or a new study appears. A page's “Updated” date only changes when its content materially changes. See the editorial policy.

Email mike@blackironathletics.com or use the contact form with the page and what's wrong, plus a source if you have one. We check it, fix the page if we got it wrong, and add a dated note to the page's “What changed” list.

Ring & Rest is published by Iron Mako Media and written by Mike M., the hands-on owner behind it. We don't list credentials we can't show you or claim testing we haven't done. More is on the about page.