Blog

Updated August 2026: rebuilt around what each maker publishes to support the words “sleep stages,” after Oura stated on August 23 that its advertised 95 percent figure is sleep-versus-wake agreement, with four-stage staging at 76 to 79 percent. WHOOP’s One plan, at $199 a year, is confirmed as the entry point to the 5.0 hardware.

Three products, three ways of counting the same thing. Sleep stage accuracy is the number to ask for, and only the Oura Ring 4 has had one published in peer-reviewed journals, at roughly 76 to 79 percent for four-stage classification. The Eight Sleep Pod 5 Core publishes a bigger number behind a bigger sample — 78 percent across more than 5,700 people — on its own engineering blog, which no outside reviewer has checked. WHOOP 5.0 publishes no four-stage figure at all. The 95 percent you may have seen on an Oura advertisement is a real number measuring a different question, and Oura said so in writing on 23 August 2026.

Sleep stages are an EEG measurement. None of these three has an EEG. Every one of them is estimating.

I’ve spent enough hurricane seasons to know a bad night’s sleep rarely matches what a ring reports. Heat and a dropping barometer move that needle more than any algorithm.

And Here Is the Short List Before the Arithmetic

• Best-documented staging: Oura Ring 4 — five peer-reviewed papers, named journals, named sample sizes, and a company post that tells you which figure measures what.
• Cheapest way in: WHOOP One at $199 a year, which includes the same WHOOP 5.0 hardware as the $239 Peak plan.
• Biggest sample, least outside checking: Eight Sleep Pod 5 Core — 78 percent staging accuracy against full polysomnography on over 5,700 subjects, self-published.

The 95 Percent Isn’t the Sleep Stage Accuracy Number

On 21 August 2026, the Clarkson Law Firm filed a proposed class action in San Francisco alleging that Oura oversold its sleep tracking. TechCrunch reported the filing the same day. The complaint quotes Oura’s marketing — “built for accuracy,” “unparalleled accuracy,” a claim of 95 percent sleep-staging accuracy against clinical labs — and argues that “Oura rings are unable to measure any of the physiological signals needed to assess sleep quality or determine sleep stages,” because “sleep happens in the brain, not on one’s finger.” Oura says it “stands behind our science, research, and accuracy claims” and will defend the case. Nothing has been decided. Treat all of it as an allegation.

What matters for a buyer is what Oura published two days later. On 23 August 2026, in a post titled Standing Behind Our Science, Oura writes that its algorithms “consistently reach 90–96% agreement with PSG” on sleep versus wake, and states plainly that this is “what the 95% figure refers to.” Two states: asleep, awake. The four-stage question — telling light, deep, REM and wake apart in each epoch — Oura puts at “roughly 76–79% agreement with human-scored PSG in healthy adults across peer-reviewed studies.”

That is a gap of 16 to 19 points between the number on the advertisement and the number behind the screen you open in the morning. Both are Oura’s. Only one of them is about sleep stages.

Here is every claim in this category I could check, and what checking it returned.

Which Sleep Stage Accuracy Claims Contradict Each Other?

Which Other Claims Did I Check?

But Two Oura Pages Give the Same Study Two Different Numbers

Read the third row again, because it is the one that changed how I scored the rest of this page. Oura’s October 2024 announcement of the Ring 4 and its new staging algorithm says the algorithm reached 79 percent four-stage agreement in a single-night inpatient study of 35 participants at Brigham and Women’s Hospital, published in Sensors, with a Cohen’s kappa of 0.65 against 0.60 for the Apple Watch and 0.55 for the Fitbit. Oura’s August 2026 post lists that same Sensors 2024 study at 76.3 percent four-stage and 92 percent two-stage, and puts the 79 percent on a different Sensors paper from 2021 covering 440 nights.

I cannot tell you which page is right. Both are Oura’s, both name the same journal and year, and a reader who lands on one of them walks away with a number the other one does not support. I have printed both and left it there.

Worth saying clearly: Oura is the only company here whose numbers can be argued about this way, and that is a point in its favour, not against it. You cannot find a contradiction in figures a company never published.

And Here Is the Sleep Stage Accuracy Each Maker Will Put in Writing

Four axes, weighted, all scoring the published record behind the phrase “sleep stages.” None of them scores how well any device works. This score is built from documentation, not from a lab, because a spec neither company will confirm in writing cannot be measured this way.

Yet Only the Peer-Review Axis Moves the Verdict

The peer-review axis is 25 points of 100. Set each axis to zero in turn and the tally reads as follows.

• Drop the published-a-figure axis: 57.5 Oura, 45.0 Eight Sleep, 6.7 WHOOP.
• Drop the peer-review axis: 62.5 Oura, 75.0 Eight Sleep, 6.7 WHOOP. Eight Sleep wins.
• Drop the model-on-sale axis: 75.0 Oura, 50.0 Eight Sleep, 6.7 WHOOP.
• Drop the measured-against axis: 67.5 Oura, 55.0 Eight Sleep, 0.0 WHOOP.

One axis flips it. If you do not care whether a number was reviewed by anyone outside the company that produced it, Eight Sleep has the better-documented claim on this table: a bigger sample, tied to the product you would buy. That is a real position and I am not going to pretend it is silly. It is just not mine.

So Oura Is the One You Can Check, and the One Being Sued

After enough hurricane seasons to distrust an unlabeled number, the Oura Ring 4 is the one I’d point a friend to, because it names its studies and journals in public. The Oura Ring 4 starts at $349, per Oura’s own 3 October 2024 launch post; its current store pages did not return a hardware price to me, and I am not going to invent one. Membership is $5.99 a month or $69.99 a year, first month free, which the store page does render. Full year one, one wearer: $418.99.

What you get for the paperwork is the ability to argue. Oura names its studies, names its journals, names its sample sizes, and separates the two-stage figure from the four-stage figure in public. That is more than either competitor does. It also filed that clarification two days after a lawsuit accused it of blurring exactly those two numbers, which is a fact about the timing and not a verdict about the science.

Skip this if: you want a staging figure measured on the Ring 4 itself. Every peer-reviewed number Oura cites ran on an earlier generation. If a ring against ring comparison is the decision you are making, our smart ring comparison scores Oura against two ring-only rivals on what each will put in writing about price and features.

And WHOOP’s Sleep Stage Accuracy Page Publishes Heart Rate

WHOOP scores 6.7 of 100 here and it is the loser of this page. Not because the strap is bad — I have no evidence either way, which is the whole problem. WHOOP’s page on how well it measures sleep leads with 99.7 percent accuracy for heart rate and 99 percent for heart-rate variability during sleep, against polysomnography, from a Central Queensland University study it names and does not cite. Its technical explainer says WHOOP data scientists trained the staging algorithm by aligning polysomnography results with strap data. It gives no agreement percentage for the result.

The only four-stage number I could find for a WHOOP device comes from outside the company: a SLEEP Advances validation of six wrist-worn trackers, published 22 March 2025 across 62 adults, which returned a Cohen’s kappa of 0.37 for the WHOOP 4.0 — fair agreement, and last but one in that set. WHOOP no longer sells the 4.0. Whether the 5.0 does better is a question no party outside WHOOP has answered in public.

Why Does WHOOP Only Publish Heart-Rate Numbers?

WHOOP publishes clean heart-rate and pricing data but no four-stage sleep figure for the hardware it currently sells. The pricing is the part WHOOP does publish cleanly. WHOOP’s own membership page lists One at $199 a year, Peak at $239 and Life at $359. The WHOOP 5.0 device, a basic charger and a Jet Black CoreKnit band come with One. Sleep, strain and recovery insights are listed identically across all three tiers — the $40 step up to Peak buys healthspan features and health alerts, not better sleep data. If sleep is why you are here, the $199 plan is the plan.

Skip this if: you want to see the staging number before you pay for the staging. There is no published figure for the hardware WHOOP currently ships. If you are buying for the recovery score rather than the sleep breakdown, our recovery wearable comparison puts WHOOP against two watches that bundle the same insight for nothing extra.

But Eight Sleep Has the Largest Sample and the Least Outside Checking

The Pod 5 Core is a mattress cover with active temperature control that reads “heart rate, HRV, sleep phases, snoring, every night,” in Eight Sleep’s own words, without anything on your body. Its buy page shows $2,799, marked down from $2,999, at the size I could retrieve. An Autopilot plan “is required for the first 12 months (cancel any time), and covers two separate users per Pod.”

Its staging evidence is the strangest mix on this page. The 78 percent figure comes from an 8 May 2024 engineering post describing a deep-learning model benchmarked against EEG on more than 5,700 subjects recorded with full polysomnography. That sample dwarfs every study Oura cites. It has also never been through peer review, and Eight Sleep’s own competitive post reaches for a YouTube reviewer rather than a journal when it wants to say the Pod beats a ring. Its heart-rate and HRV numbers — mean absolute error under one beat per minute, r-squared of 0.99, HRV correlation of 0.953 with a mean absolute error of 5.7 milliseconds — come from an internal analysis dated 25 May 2023, covering 474 nights from 163 subjects against a VitalConnect or Polar H10 ECG reference. Also internal. Also, for what it is worth, unusually specific.

If a chest-strap reference is what makes those numbers meaningful to you, the Polar H10 is the device independent testers keep reaching for; our chest strap comparison covers why.

Skip this if: sleep data is the reason you are buying. You are paying for temperature control and getting staging as a bonus. Buy the Pod for the temperature.

Which Company’s Sleep Stage Accuracy Costs the Least?

These three cannot be compared on sticker price, so compare them on the smallest cheque each company will take for a year of sleep-stage data, then divide by the number of people that cheque covers. Every input below is published by the maker. Nothing is projected forward and no lifespan is assumed.

$418.99 divided by $199.00 is 2.11. $1,549.00 divided by $199.00 is 7.78. Compared per household rather than per sleeper, the Pod comes to $3,098.00 against WHOOP’s $199.00, which is 15.57 times — so the single line in Eight Sleep’s subscription terms about covering two users halves the gap. It is the only computation on this page that moves in Eight Sleep’s favour, and Eight Sleep wrote it.

Use Eight Sleep’s other published Autopilot price instead — the $24 a month billed annually that both its membership pages show, or $288 — and the total is $3,087.00, or $1,543.50 a sleeper, 7.76 times WHOOP. The choice between those two figures is the company’s to explain, not mine.

Yet None of This Tells You Whether the Numbers Are Any Good

Some limits, stated rather than papered over.

This comparison is built entirely from what Oura, WHOOP, and Eight Sleep publish about their own products, plus the peer-reviewed and independent studies named above. Every figure above is either quoted from the maker or from a named journal. Oura’s and Eight Sleep’s store pages render prices in the browser and returned none to a fetch, so the $349 comes from Oura’s own launch announcement and the $2,799 from the size the Pod 5 Core page did return. I found no recall for Oura, WHOOP or Eight Sleep in what is publicly indexed at the US Consumer Product Safety Commission or the Canadian recalls database, which is a search of published listings rather than a query of either agency’s full file.

I also have no way to compare 76 to 79 percent against 78 percent, and neither do you. They are different studies, different reference conditions, different populations, and one has been reviewed by strangers while the other has not. Two numbers can be printed to the same decimal place and still not be the same measurement. That is the whole lesson of the 95 percent.

If you find a published four-stage figure for the WHOOP 5.0, send it to me. I will put it in the table and say where it came from.

More comparisons like this one are in our Wearable Tech category.

Apple Watch and Samsung Galaxy Watch can both take a single-lead ECG on demand — but that feature is locked to hardware that costs hundreds of dollars either way, and neither works without owning the matching phone ecosystem. AliveCor’s KardiaMobile Card does the same core job — a 30-second single-lead ECG reading you can share with a doctor — as a standalone $79 device that works with any smartphone, watch or no watch. The short version: if you already own a recent Apple Watch or Galaxy Watch, use what you have; if you don’t want to buy a whole new watch just for this, the Card is the cheaper, platform-agnostic way in.

Who Actually Needs a Personal ECG Device?

This isn’t a general-fitness feature — it’s specifically useful for people managing or screening for atrial fibrillation (AFib) and other rhythm irregularities, especially anyone who’s had an episode, has a family history, or has been told by a doctor to log symptomatic episodes. If that’s not you, a passive heart-rate sensor on any basic fitness tracker covers typical day-to-day needs, and none of the three devices here are worth buying purely for general wellness tracking.

Apple Watch: ECG App Built Into Watch Hardware

Apple’s ECG app has been available since Apple Watch Series 4 in 2018 and remains one of the earliest FDA-cleared consumer ECG features. Placing a finger on the Digital Crown for 30 seconds records a single-lead (Lead I) ECG and classifies the rhythm as sinus rhythm, AFib, or inconclusive, storing a PDF you can share directly with a doctor. It’s included at no extra cost on every compatible watch — no subscription, no per-reading fee — but it only works on Apple Watch Series 4 and later, meaning the feature itself is free while the entry ticket is a watch that starts around $399.

Apple also runs a separate, passive AFib History feature that estimates how often your heart shows signs of AFib over time, distinct from the on-demand ECG app — the two work together but measure different things: one is a snapshot you take yourself, the other is ongoing background estimation.

Samsung Galaxy Watch: Two Separate Heart Rhythm Tools

Samsung’s approach splits into two features that are easy to conflate. The first is an on-demand ECG app in Samsung Health Monitor, functionally similar to Apple’s — a single-lead reading taken by touching the watch’s frame. The second is the Irregular Heart Rhythm Notification (IHRN), a separate, passive background feature that checks for AFib-suggestive patterns via the watch’s BioActive Sensor without you doing anything. Samsung’s own announcement is explicit that IHRN “is not intended to provide a notification on every episode of irregular rhythm suggestive of AFib” and doesn’t replace a doctor.

IHRN’s current FDA clearance covers Galaxy Watch4 series and later, and it rolled out alongside the ECG app rather than replacing it. Like Apple’s setup, both Galaxy Watch heart-rhythm features are included free with the hardware — the cost barrier is the watch itself, which starts at $299.99 for the current Galaxy Watch8.

KardiaMobile Card: A Standalone ECG That Skips the Watch Entirely

AliveCor’s KardiaMobile Card is a different category of product: a credit-card-sized, single-lead (Lead I) EKG device that connects to any smartphone via an audio-based connection rather than Bluetooth, at $79 direct from Kardia. Free, it detects AFib, bradycardia, tachycardia, and normal sinus rhythm from a 30-second reading — the same core categories as either watch’s ECG app, without requiring you to own a specific brand of phone or a several-hundred-dollar watch at all.

A paid KardiaCare membership, priced around $99/year based on current third-party device comparisons (AliveCor doesn’t publish the figure prominently on its own product pages, so treat this as an estimate to confirm before buying), adds three more rhythm classifications — sinus rhythm with wide QRS, sinus rhythm with PVCs, and sinus rhythm with SVE — on top of the four free categories. A higher KardiaCare Plus tier, around $299/year by the same third-party reporting, adds a cardiologist teleconference review of your ECG. Neither membership is required to use the core device or send readings to your own doctor.

What It Actually Costs to Get a Real ECG Reading

This is the number that matters and doesn’t show up on any single product page: the true entry cost of each option, once you account for whether you already own the required hardware.

Prices reflect current manufacturer and retailer listings as of publication and change frequently — confirm the latest price with the retailer before buying.

So Which One Should You Actually Get?

If you already own a compatible Apple Watch or Galaxy Watch, there’s no reason to buy anything else — the ECG feature is already sitting on your wrist for free, and both are legitimately FDA-cleared for what they do. Between the two watches, Apple’s ECG app has the longer track record, while Samsung’s setup uniquely pairs an on-demand reading with a passive background notification in one device.

If you don’t already own either watch and the ECG feature is your main reason for buying one, the math changes: a $399+ or $299.99+ watch purchase is a steep price for a feature the $79 KardiaMobile Card performs on hardware you already have. The Card is also the only option here that doesn’t lock you into one phone ecosystem, which matters if you’re choosing on behalf of a parent or family member whose phone you don’t control.

How We Researched This Comparison

We did not use any of these three devices ourselves for this comparison. Facts and pricing were verified against each manufacturer’s own current product and clearance documentation — Apple’s and Samsung’s own newsroom announcements, and AliveCor/Kardia’s own device-comparison page — with the KardiaCare membership price specifically flagged above as third-party-reported rather than confirmed on AliveCor’s own site. See our editorial standards page for more on our process. Prices are approximate, current as of publication, and change frequently — confirm the latest price with the retailer before buying.

Frequently Asked Questions

Is the Apple Watch ECG app the same as a full 12-lead EKG at a hospital?

No. It’s a single-lead (Lead I) ECG, a much narrower snapshot than a clinical 12-lead EKG. It’s useful for catching signs of AFib and sharing a reading with a doctor, not for a full cardiac workup.

Do I need a Galaxy Watch for the Irregular Heart Rhythm Notification to work?

Yes — IHRN currently requires a Galaxy Watch4 or later, per Samsung’s own FDA clearance documentation, and works via the watch’s BioActive Sensor rather than through a phone alone.

Can the KardiaMobile Card replace a smartwatch’s ECG feature?

For the core job of taking a single-lead ECG reading, yes — it detects the same four basic categories (AFib, bradycardia, tachycardia, normal) as either watch’s app, at a fraction of the cost, though it doesn’t do anything else a smartwatch does.

Do I need a subscription to use any of these?

No. Apple’s ECG app and Samsung’s ECG/IHRN features are both included free with a compatible watch. The KardiaMobile Card’s core four-category detection is also free — a paid KardiaCare membership is optional and only adds extra rhythm classifications and, at the higher tier, a cardiologist review.

Are any of these three devices a substitute for seeing a cardiologist?

No. All three manufacturers frame their devices as screening and logging tools meant to inform a conversation with a doctor, not to diagnose heart conditions on their own. Talk to a healthcare provider about any symptoms or irregular readings.

Curious about blood pressure claims on the same watches? Our smartwatch blood pressure comparison covers a related — and often confused — set of health claims. For ring-based alternatives, see our smart ring comparison. Browse more comparisons in our Wearable Tech category.

Some links on our site may earn us a commission at no extra cost to you. Learn more.

Smart ring health metrics are wellness estimates, not diagnostic measurements, and nothing here diagnoses or treats sleep apnea or any other condition. RingConn states plainly that its products “are not medical devices and are not intended to diagnose, treat, cure, or prevent any disease.” Take a health concern to a doctor.

Updated August 2026: RingConn’s Gen 2 Air does not track sleep apnea and does not ship a pocketable charging case — those are the $299 Gen 2’s — and is rated 10 days. Oura shipped the Ring 5 on 4 June 2026.

Buy the RingConn Gen 2 Air at $199 if you want a smart ring and nothing else. Buy the RingConn Gen 2 at $299 if you specifically wanted sleep apnea pattern insights, because the Air does not have them. The Oura Ring 4 is $349 on Oura’s own store plus $69.99 a year, and Oura now also sells a Ring 5. The Samsung Galaxy Ring is $399.99 on Samsung’s buy page, needs a Galaxy phone, and cannot be recommended to an iPhone owner at any price.

In a hot, humid coastal spot, a smart ring’s always-on tracking beats checking a fogged-up watch screen. I trust a maker’s own published specs over marketing copy, because it’s a ring you wear to bed.

Which Smart Ring Should You Buy?

Prices are approximate, current as of publication, and change frequently — confirm the latest price with the retailer before buying.

Which Smart Ring Discloses Pricing Most Clearly?

Four axes, all of them scoring what each company puts in writing on its own site. None of them scores measurement accuracy. None of these three publishes a clinical validation this page could retrieve, and no ring was worn for this comparison. Weights follow how much each item changes what you can decide before checkout.

How Are These Four Scoring Axes Weighted?

Read axis two before you read the tally, because it does something that looks backwards. It scores whether the ongoing payment is stated without a qualifier, not whether there is one. Oura takes full marks for saying $5.99 a month or $69.99 a year, first month free, in plain figures on its own page. Samsung takes full marks for stating none at all. RingConn takes half, because its guide says its rings “do not require a monthly subscription fee for core health tracking.” Its Amazon listing title reads “No App Fee for Standard Features.” That’s two different qualifiers, neither with a published list of what falls outside them.

The other fractions. Axis one pays 6.0, a fifth, where two of a maker’s own pages disagree; Samsung’s is the only case. The third axis pays 20.0 to all three, which is the point of keeping it: every maker publishes its own model’s specs correctly. Axis four pays 20.0 for RingConn’s published 6.8 mm width, 2 mm thickness, and 2.5 to 4 g weight. That’s heavier, gram for gram, than the Gen 2’s published 2 to 3 g, despite the Air name. It pays 6.7 for Oura, which calls the Ring 5 “40% smaller than Oura Ring 4” with no absolute figure. It pays 0.0 for Samsung, whose product page publishes no weight.

What Happens When Each Axis Is Removed?

Set any single axis to zero and the order changes exactly once. Without axis one: 56.7, 50.0, 55.0. Drop axis three instead: 66.7, 36.0, 65.0. Without axis four: 80.0, 56.0, 65.0. Zero out axis two: 56.7, 26.0, 70.0, and RingConn wins outright. The whole Oura result rests on that one axis. That axis rewards clarity about a fee rather than the absence of one.

Smart Ring Tie-Breaker: Which One Wins?

86.7 against 85.0 is 1.7 points out of 100. That is a tie, and a tie is where this site names the one it would buy with its own money.

After enough humid mornings where a phone screen fogs before a watch face does, I’d buy the RingConn Gen 2 Air, because it publishes its size and skips the yearly fee. Oura’s 1.7-point lead is one qualifier word in RingConn’s marketing. The price difference is $150 at the counter and $69.99 every year after, and the Air publishes its physical dimensions where Oura publishes a percentage. If the qualifier ever turns into a paywall on something you use, you will have paid $199 once to find out.

Two conditions flip that. If you wanted sleep apnea pattern insights, the answer is the $299 Gen 2 and the tie-breaker does not apply, because the Air is not in that conversation. And if you are buying for someone who will not check whether a metric moved behind a paywall, Oura’s published fee is the safer purchase precisely because it is boring and printed.

Where Do Samsung’s Own Pages Disagree on Price?

Samsung’s Galaxy Ring product page opens with “From $299.99 before trade-in” and a $150 instant trade-in credit. Samsung’s buy page for the Titanium Silver, model SM-Q50XNZSAXAR, lists $399.99 against every one of eleven sizes, 5 through 15, with no promotional price shown. The difference is $100 and both figures are published by Samsung.

This page uses $399.99, because that is the number on the page where you press buy. But a buyer who reads the marketing page first and the buy page second has been told two things, and the Ledger scores that at 6.0 of 30.

A second mismatch sits alongside it. Samsung’s product page describes a sizing kit offering “9 sizes, from 5 to 13,” while the buy page sells sizes 5 through 15. Two purchasable sizes have no way to be tried on first, on a product whose entire fit story is that you wear it for 24 hours before deciding.

Samsung’s battery figures split the same way. Its product page states up to 7 days on standard sizes and up to 6 days on the largest, sizes 12 and 13, with up to 14 days when a full cradle charge is added to that.

How Does the Oura Ring 5 Compare to the Ring 4?

Oura’s store renders prices per finish, which is more than Samsung’s marketing page manages. Oura Ring 5 is $399 in Silver and Black and $499 in Gold, Deep Rose, Stealth and Brushed Silver. The Ring 4 is $349 in Silver and Stealth, with Gold at $399 down from $499. Ring 4 Ceramic sits at $399, down from $499 in both finishes.

The Ring 5 shipped 4 June 2026, per Tech Advisor’s launch coverage, and Oura’s own Ring 4 page now describes the Ring 5 as “40% smaller than Oura Ring 4.” The Ring 4 has not been withdrawn and is $50 cheaper. That is a live choice between two current Oura rings, not a discontinuation.

Oura’s membership is the clearest ongoing cost in the category: “$5.99 USD/month or $69.99 USD/year,” with “New members get their first month free,” printed on Oura’s own page. Twelve months at $5.99 is $71.88, so the annual plan saves $1.89 a year. That is the entire arithmetic, and it is on Oura’s page rather than inferred.

Which Smart Ring Is the Worst Match for You?

Skip the RingConn Gen 2 Air if sleep apnea pattern insights were the reason you were interested, or if you want a charging case you can put in a pocket. Both are on the $299 Gen 2. Skip it too if the word core in “core health tracking” bothers you, because RingConn does not publish what sits outside it.

Skip the Oura Ring 4 if a recurring bill is the thing you are trying to avoid. It is $349 plus $69.99 a year, and Oura is candid about that rather than apologetic. Skip it as well if you were buying it for being the newest thing Oura makes, because since 4 June 2026 it has not been.

Skip the Samsung Galaxy Ring if you carry an iPhone or a non-Samsung Android; Samsung’s own page requires “a compatible Samsung Galaxy smartphone” and the Samsung Health app. It is the named loser here at 56.0 of 100, and not for its hardware: it loses on publishing two prices for one ring and no weight at all, and on selling two sizes its own sizing kit does not cover.

Which Numbers Here Are Least Verifiable?

No independent clinical validation of RingConn’s sleep apnea pattern insights was retrieved from any source checked for this page. Samsung publishes no weight for the Galaxy Ring on its product page, so that cell scores zero rather than borrowing a figure from a review. Oura’s own pages did not return an absolute size for the Ring 4, only a relative one for the Ring 5. And Forbes’ Ring 5 launch coverage returned a 403 to a fetch, so the launch date and price here come from Tech Advisor’s reporting, named in the sentence that uses them.

None of these three companies publishes a clinical accuracy study on its own product pages, and all three sell wellness estimates rather than measurements. That is a limit on what any comparison of them can say, including this one.

Nearest Comparisons on This Site

If the health claim is what you are weighing rather than the ring, our look at blood pressure on a smartwatch separates a cleared reading from a marketed one, and which scale numbers to trust does the same for body composition. For the subscription question on a wrist instead of a finger, see the cost after purchase on smart scales. More in Wearable Tech.

Smartwatch blood pressure monitoring works completely differently across three devices. Only the Omron HeartGuide gives you a real reading the way a doctor’s cuff does. Apple Watch Series 11 only sends a passive notification if it detects hypertension-like patterns over time. It never shows a systolic/diastolic reading. Samsung’s Galaxy Watch does show an actual number, but it’s an uncleared “wellness feature.” That feature needs monthly recalibration against a real cuff to stay meaningful. Omron’s HeartGuide is the outlier: it’s a true inflatable cuff built into a watch band. It’s also the only one of the three that’s FDA-cleared as an actual blood pressure monitor.

A wellness feature on a gadget and a real medical reading are two different things. Even when the app shows a similar-looking number, they aren’t the same. So I’ve learned to check what a device is cleared to do before trusting what it shows.

Which smartwatch blood pressure monitoring option works best?

After years of doctor’s-office cuff checks, the Omron HeartGuide is where I’d start, because it’s cleared for a real reading, not a wellness guess. The Omron HeartGuide is the only FDA-cleared blood pressure monitor of the three, at $499. Meanwhile, the Samsung Galaxy Watch shows a real number for $299.99 but isn’t FDA-cleared. The Apple Watch Series 11 only sends a passive hypertension notification, with no number at all.

Optical vs. oscillometric: what’s the real difference?

Optical sensors estimate blood pressure from light reflected off your skin. Oscillometric sensors, though, physically inflate a cuff against your wrist the same way a doctor’s cuff does. Only one device in this comparison uses that second method. The first is optical — a light-based (PPG) sensor watches how your blood vessels respond to each heartbeat. From that, it estimates pressure or flags a pattern. The second is oscillometric — an actual miniature air cuff inflates against your wrist and measures pressure mechanically. That’s the same physical principle as the cuff at your doctor’s office. Only one device in this comparison uses the second method.

That distinction matters because the FDA regulates the two very differently. A device that displays an actual number and is marketed for managing a diagnosed condition typically needs medical-device clearance. A feature like that flags a pattern for you to discuss with a doctor. Without ever displaying a number, it can qualify for a lighter review pathway. In some cases, it needs no review at all if it’s framed purely as “wellness.” That’s exactly the fork in the road between our three devices.

Apple Watch Series 11: Notification, Not a Number

Apple’s hypertension notification feature works entirely in the background. It was introduced with Apple Watch Series 11 and watchOS 26. According to Apple’s own September 2025 announcement, the feature “uses data from the optical heart sensor to analyze how a user’s blood vessels respond to the beats of the heart.” That review happens passively over rolling 30-day periods. If the algorithm sees a consistent pattern associated with chronic high blood pressure, it sends a notification. That’s the entire output. There is no systolic or diastolic number anywhere in the experience.

The feature received FDA clearance in September 2025. It’s available on Apple Watch Series 9 and later, plus Apple Watch Ultra 2 and later, running watchOS 26. That means it isn’t exclusive to the newest Series 11 hardware, though Apple launched it alongside that model. Apple’s guidance for anyone who gets a notification is simple: log blood pressure with a separate cuff for seven days. Then share those readings with a doctor. That underscores that the watch is a screening trigger, not a diagnostic tool. Apple Watch Series 11 (GPS, 42mm) starts at $399 at retail. It’s been discounted to around $299 repeatedly through 2026, according to retailer listings.

Samsung Galaxy Watch: Not FDA-Cleared

Samsung takes the opposite approach. Its Blood Pressure Monitoring feature is built into the Samsung Health Monitor app. It displays an actual systolic and diastolic reading plus heart rate, using the watch’s optical sensors and a pulse-wave-analysis algorithm. It’s compatible with Galaxy Watch4 and later running Wear OS 4.0 or newer. Samsung began a phased US rollout of the feature on April 6, 2026, after years of it being US-restricted.

The catch is regulatory, not technical. Samsung has been explicit that the feature “doesn’t require FDA clearance”, since it’s a wellness feature, not a medical device. The company’s own guidance also says not to treat it as “an alternative to a medical-grade blood pressure monitor.” On top of that, the watch needs recalibrating against a real cuff roughly every 28 days to stay accurate. Skip that, and Samsung’s own documentation says the readings drift. Galaxy Watch8 (40mm, Wi-Fi/Bluetooth) starts at $299.99 directly from Samsung. Most of that price range from Watch4 onward supports the feature.

Omron HeartGuide: FDA-Cleared Smartwatch Blood Pressure Monitoring

Omron’s HeartGuide is a fundamentally different product category wearing a smartwatch’s clothing. Instead of estimating pressure from light and an algorithm, it uses a miniature oscillometric pump built into the watch band. That pump uses the same mechanism as a standard clinical cuff, inflating against your wrist to take a real measurement. Omron received 510(k) FDA clearance for the HeartGuide on January 8, 2019. As far as we can verify, it remains the only wrist-worn device with that specific clearance for blood pressure measurement. That’s rather than a wellness estimate or a notification.

That accuracy comes with real tradeoffs. The inflation cycle takes roughly 30 seconds and feels like a scaled-down version of a normal cuff reading. That’s noticeably different from the instant, passive readings of the other two watches. It’s also the most expensive device here by a wide margin, at $499 direct from Omron Healthcare. Its smartwatch features — notifications, step tracking — are secondary to its core job as a medical device you wear.

What does each device give you, and what does it cost?

The Omron HeartGuide is the only one of the three that shows an FDA-cleared blood pressure number, at $499. The Samsung Galaxy Watch shows a number too, but isn’t FDA-cleared, at $299.99. Meanwhile, the Apple Watch Series 11 shows no number at all, starting at $399.

Prices reflect current manufacturer and retailer listings as of publication and change frequently.

Which Smartwatch Blood Pressure Monitoring Feature Should You Trust?

If you want an early warning without buying a new device, the Apple Watch’s notification feature is the lowest-friction option. It works passively on hardware many people already own. Its entire job is to tell you when to go get a real reading elsewhere. It’s a smoke detector, not a thermometer, and that’s a legitimate, FDA-cleared use case on its own terms.

If you have already-diagnosed hypertension and want to log daily trends without a separate cuff, consider the Galaxy Watch. It’s the middle path — go in accepting that “not FDA-cleared” is a real limitation, not a technicality. Also know that skipping the 28-day recalibration undermines the entire feature. It’s a trend tool, not a diagnostic one.

If you need a number a doctor can rely on, the Omron HeartGuide is built for that job. That’s true whether you’re titrating medication, managing a diagnosed condition closely, or your doctor has specifically asked for home readings. It costs more and takes longer per reading because it’s doing something fundamentally more rigorous than the other two.

How We Compared These Blood Pressure Monitoring Smartwatches

This comparison draws on each device’s FDA clearance status and published specs. It also looks at how each device measures or estimates blood pressure. Our conclusions are built from each manufacturer’s own specifications, FDA clearance documents, and outlet reporting on each feature’s rollout. We cross-referenced all of that against each other, rather than relying on any single source. Where we cite a price or clearance date, we verified it directly against the manufacturer’s current listing. Or, we checked the relevant FDA filing. You can read more about our process on our editorial standards page. Prices are approximate, current as of publication, and change frequently — confirm the latest price with the retailer before buying.

Published August 7, 2026. Updated September 8, 2026.

Blood Pressure Monitoring Smartwatches: FAQ

Can any smartwatch measure blood pressure like a doctor’s cuff?

Not in the traditional sense, with one narrow exception. Omron’s HeartGuide uses a true inflatable oscillometric cuff built into the band and is FDA-cleared for actual blood pressure measurement. Apple Watch and Samsung Galaxy Watch both use optical sensors instead. Apple only sends a hypertension notification with no number. Samsung’s shows a number but isn’t FDA-cleared and needs monthly recalibration.

Is the Apple Watch hypertension alert a blood pressure reading?

No. Apple’s feature only sends a notification if it detects a pattern consistent with chronic hypertension over a rolling 30-day window. It never displays a systolic or diastolic number. Apple’s own guidance is to confirm any alert with a real blood pressure cuff over the following week. Then share those readings with a doctor.

Is Samsung’s Galaxy Watch blood pressure feature FDA-approved?

No. Samsung has said the feature doesn’t require FDA clearance because it’s classified as a wellness feature, not a medical device. The company explicitly advises against treating it as a substitute for a medical-grade blood pressure monitor.

Why does the Galaxy Watch need to be recalibrated with a cuff?

It estimates blood pressure from optical pulse-wave data rather than measuring it directly. Because of that, its accuracy drifts over time as your baseline vascular signals change. Samsung requires recalibrating against a traditional cuff roughly every 28 days to keep the estimate meaningful.

Is the Omron HeartGuide worth the extra cost over a smartwatch?

If you need a genuinely reliable number, yes — it’s the only device here cleared and built for that job. That’s true whether you’re managing diagnosed hypertension, adjusting medication, or tracking readings a physician will rely on. If you just want a general early-warning signal, a smartwatch’s notification feature may be enough.

Do any of these devices replace regular doctor visits?

No. All three manufacturers frame their features as screening or trend tools. Those tools are meant to prompt a conversation with a healthcare provider, not to replace clinical monitoring or diagnosis. Talk to a doctor about how to interpret any reading or notification from a consumer wearable.

Curious how other health wearables stack up? Our comparison of Abbott Lingo vs. Dexcom Stelo vs. Signos glucose monitors covers a similar accuracy-vs-convenience tradeoff for at-home health tracking, and our smart scales vs. body composition monitors comparison looks at another wrist-adjacent health metric worth double-checking before you trust it. For more wearable comparisons like this one, browse our full Wearable Tech category.