The best smart rings for men, ranked on size, toughness and fees

Large sizes: who actually goes to 15

If you wear a big ring size, start here, because size rules rings out before anything else does. Of the rings we cover, three go up to a size 15: the RingConn Gen 3, the Samsung Galaxy Ring and the Oura Ring 4. The RingConn Gen 2, Gen 2 Air and Ultrahuman Ring PRO stop at 14. Oura's newer Ring 5 stops at 13, which is why it isn't on this list. Circular Ring 2 also stops at 14 and runs about half a size large by Circular's own note.

Brand sizes aren't interchangeable, with each other or with your wedding band. RingConn says 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.” No ring we cover lists a size 16. If your jewelry size is near the top of the range, get the sizing kit before the ring: RingConn ships Gen 3 only after you confirm your size, and Samsung's Amazon listings are titled “Size First w/Sizing Kit.” Our guide to smart rings in large and small sizes goes through the top end size by size.

A bigger ring holds a bigger battery

Large sizes have one quiet advantage. Oura's product safety page lists a “15mAh (US6) - 22mAh (US13)” battery, so a size 13 carries about half again the capacity of a size 6 (Oura Support). Samsung gives its longest rating, up to 7 days, to sizes 12 and 13, and up to 6 days to smaller sizes. It doesn't state a figure for sizes 14 and 15, which it added in January 2025. RingConn and Ultrahuman quote one battery figure for all sizes on the pages we checked.

Titanium and water ratings

Every ring here uses titanium in some form. The durability numbers brands actually publish are water ratings, so that's what we compare:

The fine print matters more than the headline figure. Samsung's 10ATM rating means “up to 100m of water for up to 10 minutes,” and its IP68 rating covers up to 6 feet for 30 minutes. Oura calls Ring 4 “suitable for sauna and water sports but not diving.” Neither is a dive rating. Ultrahuman adds a safety feature that matters if you work with your hands: ProRelease Technology “enables Ring PRO to be cut apart more easily in the event of swelling or injury to the finger” ( Ultrahuman). None of the brands here publishes a scratch or drop test we could source. For showers, pools and saunas ring by ring, see is a smart ring waterproof.

Lifting, training and workout heart rate

A ring on a barbell hand takes knocks, and none of these brands publishes a lifting guideline we could source. Third-party silicone covers sold for smart rings are one option, as long as you check the fit for your model and size. Our guide to the best smart ring for weightlifting covers covers, fit and which ring to pick if the gym is where you'll wear it hardest.

Workout heart rate is the weak spot for every ring with published reviewer data. DC Rainmaker found Oura Ring 5's heart rate “largely pretty good” against a Polar H10 on indoor rides and road runs, but on a trail descent “the HR accuracy basically falls apart for the entire rest of the run.” Gadgets & Wearables found the RingConn Gen 2 “consistently reported higher values” than a chest strap on runs. Tech Advisor's Circular Ring 2 reviewer went further: “I've not tested a smart ring that I really think does a good job of tracking heart rate during exercise.”

What each pick costs to own

The Oura Ring 4 is the only pick with a required fee: $209.97 over three years on the annual plan, $349.95 over five, or $215.64 over three years paying $5.99 a month. Everything else costs nothing after checkout, though Ultrahuman sells optional PowerPlugs (Cardio Adaptability is $24/year). The brand-by-brand breakdown is in what a smart ring really costs over three years.

How we ranked them

Each ring carries its score from our published rubric: cost of ownership 30%, evidence of accuracy 25%, battery 15%, sizing and fit 10%, data ownership 10% and phone support 10% (reasoning on our methodology page). We haven't worn or lab-tested any of them; every fact comes from brand pages, named reviewers and studies linked below.

We follow the scores with one exception. The RingConn Gen 3 (8.1) ranks above the Gen 2 (8.2) because it does the three things this page is about better: it goes to size 15, adds a 10ATM rating on top of IP68, and claims the longest single charge RingConn offers. Two rings were left off. The Oura Ring 5 tops out at 13, and the Circular Ring 2 has no published validation, runs half a size large and is sold only on Circular's store. Both appear in our best smart rings ranking.

The picks in context

1. RingConn Gen 3: best for men

The Gen 3 checks every box this page cares about. It comes in ten sizes from 6 to 15, it's titanium (2.3 mm at its thinnest, per The Gadgeteer), it's rated IP68 and 10ATM, and RingConn claims up to 14 days a charge and 150+ days in total with its charging case. The Gadgeteer's reviewer got about 10 days with vibration alerts on. There is no subscription and, per that review, “no locked tier, no upsell screen anywhere in the app.” It also adds Vascular Health Insights, which turn nighttime patterns and optional cuff readings into blood pressure trends, and Sleep Apnea Pattern Insights, which RingConn says “detects breathing interruptions and oxygen drops to address sleep apnea risks.” RingConn is careful here: “we're not claiming to replace medical devices.” No study has tested Gen 3 itself, and it showed “Out of stock” on RingConn's store when we checked, though Amazon listed it. More in our RingConn Gen 3 review.

2. RingConn Gen 2: the longest-proven RingConn

If you wear a 14 or smaller, the Gen 2 is the ring with the most behind it among the no-fee options: 10-12 days a charge, up to 150 days with the included case, an aerospace-grade titanium alloy shell, IP68 to 100 meters, and support for iOS 17 and Android 10 or newer. It's the only no-fee ring with a chest-strap comparison of its own, a 2026 preprint (Tao et al., not peer-reviewed) that found a heart rate bias of -0.42 bpm against a Polar H10 in seated athletes. That's rest, not training, and Gadgets & Wearables found it read high on runs. Its “90.7% Sleep Apnea Monitoring Accuracy” is RingConn's own claim. See the RingConn Gen 2 review or RingConn Gen 3 vs Gen 2.

3. RingConn Gen 2 Air: the lower-cost option to size 14

Same sizes as Gen 2 (6-14), same no-fee app, same iOS and Android support, for less; RingConn lists it below Gen 2 and Gen 3 on its own store. The trade-offs: no charging case, no sleep apnea monitoring, up to 10 days a charge with 90-minute fast charging, and a titanium steel shell with PVD coating rather than Gen 2's titanium alloy. No study has tested it. Our Gen 2 vs Gen 2 Air comparison and RingConn Gen 2 Air review spell out the difference.

4. Ultrahuman Ring PRO: titanium unibody, if you can wait

The PRO is built for abuse on paper: a titanium unibody rated to 100 meters, ProRelease Technology for easier removal if a finger swells or is injured, and the longest claimed battery we found, up to 15 days and 45 with the PRO Charging Case in the box. Sizes run 5-14 with a free sizing kit, and no fee is required. But it's a US pre-order from Ultrahuman's own store (“ships October 10th onwards” when we checked, after earlier dates slipped), it isn't sold on Amazon.com, Ultrahuman doesn't state its phone requirements on the US pages we checked, and its only published data is an in-house pilot on the older Ring AIR. The Ultrahuman Ring PRO review has the full story.

5. Samsung Galaxy Ring: size 15 for Samsung phones

Samsung added sizes 14 and 15 in January 2025, so the Galaxy Ring now runs 5-15 with a complimentary sizing kit. It has a titanium frame, 10ATM and IP68 ratings, a charging case in the box (up to 14 days total, per Samsung) and no app subscription. It ranks fifth because it's Android only, Double Pinch and Find My Ring don't work on other Android brands, Energy Score insights need a Samsung Galaxy AI phone, and we found no peer-reviewed validation of it. Samsung has announced an FDA-cleared sleep apnea risk feature for the ring this fall; until it ships, treat it as coming, not live. See the Galaxy Ring review and RingConn vs Galaxy Ring.

6. Oura Ring 4: size 15 and the best evidence, if you'll pay

Oura Ring 4 runs 4-15, in titanium with a PVD or DLC coating, rated to 100 meters. It's the Oura model Dial et al. (2025) tested against a Polar H10 across 536 nights, with resting heart rate error of 1.94% and HRV error of 5.96% (13 adults, nighttime only; funded by the US Air Force Research Laboratory). No ring on this list has better evidence. It ranks last because the membership never ends: without it, Oura says you'll only see your three daily scores, battery, profile, settings and Explore content. It's also off Oura's current ring list, though still listed on Amazon, and its battery is excluded from Oura's one-year warranty. Our Oura Ring 4 review and is the Oura Ring worth it weigh the fee.

What to check before you buy

1. Your size, measured with that brand's kit. Especially at 13 and up, where one brand's top size may not match another's. Our smart ring sizing guide walks through it, and smart ring sizing compared explains why no official conversion between brands exists.
2. Which finger. Oura recommends the index finger for best accuracy. If you lift, think about which finger takes the least contact with a bar; see which finger to wear a smart ring on.
3. Your phone. Galaxy Ring is Android only, with its best features on Samsung phones. RingConn needs iOS 17 or Android 10 or newer.
4. Whether you need a charging case. RingConn Gen 3 and Gen 2, Ultrahuman Ring PRO and Galaxy Ring include one; Gen 2 Air and Oura Ring 4 don't. If you travel for work, the case is worth more than a spec sheet suggests.
5. The warranty on the battery. Oura excludes batteries as consumables. RingConn excludes normal capacity loss but sells optional two- and three-year protection in the US. See our warranty and returns guide.

Mistakes to avoid

• Ordering your wedding-band size. Smart ring sizing is brand-specific, and a ring that's too tight is miserable to sleep in.
• Assuming the newest Oura comes in your size. Ring 5 stops at 13; Ring 4 goes to 15.
• Reading a water rating as a dive rating. Samsung's 10ATM is “for up to 10 minutes,” and Oura rates Ring 4 for sauna and water sports “but not diving.”
• Training by ring heart rate. Reviewers found rings unreliable on runs and trail descents. Use a chest strap for zones.
• Treating blood pressure or apnea insights as a diagnosis. RingConn says Gen 3 is “not a medical device,” and we found no smart ring with an FDA-cleared blood pressure feature. Our guide on whether a smart ring can measure blood pressure explains the gap.