The Galaxy Ring has been on sale since July 2024 (Samsung Newsroom). It runs on Samsung Health, the same app as the Galaxy Watch, so most of what the app does with HRV is shared. This page covers what is different on the finger and what Samsung says about the ring itself; Samsung Galaxy Watch HRV covers the watch.
Documentation checked: 22 October 2026. Samsung updates Samsung Health often, so details can change.
What HRV number the Galaxy Ring shows
Samsung uses two names for it. Vitals lists “heart rate variability” as one of five measures, with heart rate, blood oxygen, respiratory rate Breathing rate How many breaths you take a minute. It moves HRV on its own: slower, deeper breathing makes the beat-to-beat swing larger, and below about 9 breaths a minute it shifts from the HF band into LF. More about Breathing rate and skin temperature (Samsung Health, US). The Energy Score uses “Sleeping Heart Rate Variability” (Samsung Newsroom, July 2024). Neither page names the statistic, whether RMSSD RMSSD Root mean square of successive differences: an HRV metric built from how much each heartbeat interval differs from the next, in milliseconds. It mainly reflects vagal activity. More about RMSSD , SDNN SDNN The standard deviation of all NN intervals in a recording, in milliseconds. It measures overall variability, and its value depends strongly on how long the recording lasts. More about SDNN or something else, or how long each sample runs.
RMSSD and SDNN are different measures of the same beats and give different numbers (Task Force, 1996). Without the formula, you cannot set the ring’s value against published norms or against another brand’s reading.
The ring reads your pulse with what Samsung calls an Optical Bio-signal Sensor, next to a skin temperature sensor and an accelerometer (Samsung, Galaxy Ring). Like a watch, it times the pulse wave arriving at the skin, while a chest strap times the heart’s electrical beat; PPG: how your watch reads your pulse explains the difference.
When the ring measures HRV
Samsung describes the ring’s HRV only at night. The Energy Score uses sleeping HRV, and Samsung’s support page says the ring uses HRV “to detect transitions between sleep stages” (Samsung Support). For the watch, Samsung also mentions HRV while you rest during the day; for the ring it documents no daytime reading.
Samsung Research adds that its energy predictions are more accurate when sleeping heart rate and HRV are “analyzed during a stable state of sleep” (Samsung Newsroom, June 2024). It does not say which part of the night that is. Oura averages the whole night and Polar uses about four hours early on, and the HRV by device guide shows how much the window changes the number. Samsung has not published the ring’s window, so you cannot line its value up with either.
Energy Score: where HRV counts
Energy Score is Samsung’s daily readiness score Readiness score A single number, often out of 100, that a device builds from your HRV, resting heart rate, sleep and other inputs to suggest how ready you are for the day. The weighting is not published. More about Readiness score , the same on the ring and on the Galaxy Watch4 and later. Samsung names four factors: sleep, activity, sleeping heart rate and sleeping HRV (Samsung Newsroom, July 2024). Samsung Research describes how the score reads each one (Samsung Newsroom, June 2024):
- Sleep: average sleep over seven days, how regular your sleep and wake times are, and how quickly you fall asleep.
- Activity: yesterday’s workload against your usual load, using the acute:chronic workload ratio.
- Sleeping heart rate and HRV: your recent values compared with your own longer-term trend.
Samsung Research took age and gender into account when it set how much each factor counts, and does not publish the weights. The score needs at least the previous day’s activity, sleep and sleeping heart rate, synced to Samsung Health, and a compatible Galaxy AI phone (Samsung Newsroom, July 2024).
What is in a readiness score?
From the makers' own documentation
- HRV : named by the maker Heart rate variability.
- Resting heart rate : named by the maker Sleeping heart rate.
- Breathing rate : not named Not named by the maker.
- Sleep : named by the maker Sleep time average, sleep time consistency, bed and wake time consistency, and sleep timing.
- Temperature : not named Not named by the maker.
- Activity or load : named by the maker Previous day activity.
Samsung's Energy Score names 4 of the six inputs: HRV, resting heart rate, sleep and activity or load. Samsung lists the metrics the score combines and nothing about their weights.
A list of scores, one per device, with six inputs for each: HRV, resting heart rate, breathing rate, sleep, temperature and activity or load. Samsung's Energy Score names 4 of the six inputs: HRV, resting heart rate, sleep and activity or load. Samsung lists the metrics the score combines and nothing about their weights.
Because HRV is one of four inputs, a low Energy Score does not tell you that HRV fell. A short night or a hard workout yesterday can pull the score down while HRV holds steady. Recovery scores explained sets it beside other makers’ scores.
Where to find HRV in Samsung Health
The ring has no screen, so everything is in the Samsung Health app on your phone.
- Vitals. HRV appears with the other four sleep measures. Samsung’s Australian page says Vitals needs Samsung Health 7.0 or later, a phone on Android 13 or later and at least 7 nights of wearing a Galaxy Watch or Galaxy Ring to sleep (Samsung Health, Australia). Samsung’s US support page describes Vitals only for the Galaxy Watch9 and Watch Ultra2 (Samsung Support), so if you own only the ring, check whether your app offers it.
- Energy Score. Sleeping HRV is one of its four factors.
- Sleep. HRV works behind the stage graph. Samsung does not describe a separate HRV readout there.
On your finger
Galaxy Ring
An optical sensor reads your pulse at the finger while you sleep, beside a skin temperature sensor and an accelerometer.
In Samsung Health
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Sleep stages
HRV helps detect the move from one sleep stage to the next.
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Energy Score
Sleeping HRV and sleeping heart rate, compared with your long-term trend, beside sleep and activity.
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Vitals
Heart rate variability with four other sleep measures, after at least 7 nights.
Out of the app
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Download personal data
Saves files to your phone. Samsung does not list what they hold.
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Health Connect
Samsung’s list of shared data includes steps, exercise, heart rate and sleep. HRV is not on it.
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Samsung Health Data SDK
Lets other apps read your Energy Score. HRV is not one of its data types.
Three columns joined by arrows. First, the Galaxy Ring on your finger, whose optical sensor reads your pulse while you sleep. Second, Samsung Health on your phone, which uses HRV in three places: sleep stages, where HRV helps detect the move from one stage to the next; Energy Score, which compares sleeping HRV and sleeping heart rate with your long-term trend beside sleep and activity; and Vitals, which shows heart rate variability with four other sleep measures after at least 7 nights. Third, three ways out of the app: Download personal data, which saves files to your phone without Samsung listing what they hold; Health Connect, whose list of shared data includes steps, exercise, heart rate and sleep but not HRV; and the Samsung Health Data SDK, which lets apps read Energy Score but has no HRV data type.
Where do I find HRV on my device has the same steps for other brands.
Does the Galaxy Ring need a subscription?
No. At launch Samsung said the ring’s data and insights sit in Samsung Health “without a subscription” (Samsung Newsroom, July 2024). On Samsung Health’s US page, the content that needs a paid subscription is optional premium workouts from iFIT (Samsung Health, US). The ring launched at $399.99 (Samsung Newsroom, July 2024). On 22 October 2026 Samsung’s US store still gave $399.99 as the list price and offered the ring “from $299.99 before trade-in”, a discount that may not last (Samsung, Galaxy Ring).
You do need the right phone. Samsung requires an Android phone running Android 11 or later, and the Energy Score needs a compatible Samsung Galaxy AI phone (Samsung Newsroom, July 2024). For comparison, Oura’s app shows only its three daily scores without a membership (Oura Member Care).
Getting your data out
- Download personal data. In Samsung Health, open More options, then Settings, then Download personal data. The files land in My Files, under Downloads, in a Samsung Health folder (Samsung Support). Samsung does not list which files you get or whether the nightly HRV is one of them.
- Health Connect. Samsung’s developer FAQ says activity data such as steps and exercise, heart rate and sleep are synchronised with Android’s Health Connect (Samsung Developer). HRV is not on that list.
- Other apps. Samsung’s Health Data SDK lets apps read the Energy Score, heart rate, sleep and skin temperature; HRV is not one of its data types (Samsung Developer).
If you want beat-to-beat data you can analyse yourself, a chest strap with a free app is the dependable route; cheapest HRV tracking explains the setup.
How accurate is Galaxy Ring HRV?
No published study has tested it. We searched PubMed, Europe PMC and Crossref on 22 October 2026 and found no peer-reviewed paper that compared the Galaxy Ring’s HRV with an ECG ECG A recording of the heart's electrical activity, taken with electrodes on the skin. ECG-based RR intervals are the reference standard for measuring HRV. More about ECG or a chest strap. The ring was not part of the 2025 Dial study, which tested Oura, WHOOP, Garmin and Polar devices overnight against a Polar H10 (Dial and colleagues, 2025).
Peer-reviewed HRV studies of rings and Samsung wearables in our tracker
Validation tracker
Year the study was published
We searched PubMed, Europe PMC and Crossref for a Galaxy Ring HRV study on 22 October 2026 and found none. The Gear Sport is an older Samsung watch, and its researchers analysed the watch’s pulse signal themselves rather than a number from the app.
Sources: Kinnunen and colleagues, 2020, Stone and colleagues, 2021, Miller and colleagues, 2022, Cao and colleagues, 2022, Sarhaddi and colleagues, 2022, Dial and colleagues, 2025, Tao and colleagues, 2026. Every study with its numbers is in the device validation tracker.
A timeline from 2020 to 2026 with one row per device, from the device validation tracker. Oura Ring Gen 4: Dial and colleagues, 2025, 13 people, asleep. Oura Ring Gen 3: Dial and colleagues, 2025, 13 people, asleep. Oura Ring Gen 2: Stone and colleagues, 2021, 5 people, at rest and Miller and colleagues, 2022, 53 people, asleep. Oura Ring: Kinnunen and colleagues, 2020, 49 people, asleep and Cao and colleagues, 2022, 35 people, asleep. RingConn Gen 2: Tao and colleagues, 2026, 64 people, at rest. Samsung Gear Sport: Sarhaddi and colleagues, 2022, 28 people, asleep and through the day. Samsung Galaxy Ring: no study, from going on sale in July 2024 to our search in October 2026. We searched PubMed, Europe PMC and Crossref for a Galaxy Ring HRV study on 22 October 2026 and found none. The Gear Sport is an older Samsung watch, and its researchers analysed the watch’s pulse signal themselves rather than a number from the app.
The nearest evidence comes from other devices:
- Other rings. In the Dial study, the Oura Ring Gen 4’s overnight RMSSD had a concordance of 0.99 with the strap and an average error of 5.96% (Dial and colleagues, 2025). So a finger ring can track overnight HRV well, though the result belongs to Oura’s sensor and software. Oura HRV has the detail.
- An older Samsung watch. In 28 adults over 24 hours, researchers analysed the Gear Sport’s pulse signal against a chest ECG. During sleep, its RMSSD correlated with the ECG at 0.778 and read 18.24 ms low on average; while people were awake, the correlation fell to 0.251 (Sarhaddi and colleagues, 2022). Samsung Galaxy Watch HRV puts that study in context.
Until someone tests it, treat the ring’s HRV as a trend from a device with no published error.
How to read the Galaxy Ring’s HRV
- Compare it only with your own past nights. Without a formula or a window, you have nothing else to set it against.
- Read weeks, not nights. No one has published how far a single night can be off, so a one-night drop tells you little. A shift that lasts a week tells you more.
- Look behind the Energy Score. Check which of the four factors moved before blaming HRV.
- Keep the ring on the same finger, snug. Samsung’s support page asks for a snug fit (Samsung Support). Moving fingers starts a new series.
- Know which device recorded the night. Samsung says wearing a Galaxy Watch and the ring together gives Samsung Health a wider range of data (Samsung Newsroom, July 2024), but it does not say whose HRV it uses on a night you wear both.
- Expect a step after an update. See can a software update change my HRV.
- Do not mix brands in one trend. An Oura or Garmin number is a different series; how long until my HRV baseline is reliable covers starting over.
When to talk to a doctor
Samsung says the ring’s sleep and Energy Score features are for general wellness and not for diagnosing anything, and that Vitals is not for diagnosing disease (Samsung Newsroom; Samsung Health, US). Talk to a doctor if low HRV or a run of low Energy Scores comes with feeling unwell, lasting fatigue, palpitations, dizziness, fainting or chest pain, whatever the number says.