Do these 3 things before closing this tab:
1Repair Windows errors before they cause bigger problems2Scan for outdated or missing drivers - takes under a minute3Clear out junk files and repair common Windows errorsOura Ring 4 is best understood as a discreet sleep and wellness tracker, not a medical device or sports watch. It records sleep-related signals and personal trends, but the research reviewed here does not establish a universal Ring 4 sleep-accuracy percentage or prove that every sleep-stage estimate is exact. Its membership unlocks detailed insights and personalized guidance, so the recurring fee is a central part of the buying decision.
Oura Ring 4 at a glance
| Category | What to know |
|---|---|
| Tracks | Sleep-related measures, heart rate, HRV and respiration during sleep, blood oxygen during sleep, temperature variation, and movement |
| Sizes | 4–15; use the Ring 4 sizing kit |
| Width and thickness | 7.9 mm wide and approximately 2.88 mm thick |
| Weight | 3.3–5.2 g, depending on size |
| Water resistance | 100 m / 328 ft; not intended for diving |
| Typical battery life | 5–8 days per charge, according to Oura; actual results vary |
| Typical charging time | 20–80 minutes, according to Oura |
| US membership | $5.99 monthly or $69.99 annually before tax; new members get one included month |
What Oura Ring 4 tracks
Oura says Ring 4 uses red and infrared LEDs for blood-oxygen sensing during sleep, green and infrared sensors for heart rate, and for HRV and respiration rate during sleep. A temperature sensor tracks average body-temperature variations, while an accelerometer records movement and activity. With membership, the app provides features including detailed sleep analysis, stress, activity, heart health, metabolic health, and women’s health insights.
| # | Preview | Product | Price | |
|---|---|---|---|---|
| 1 |
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OURA Ring 4 Smart Ring - Silver - Size 9 | $349.00 | Buy on Amazon |
| 2 |
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OURA Ring 4 Smart Ring - Silver - Size 8 | $349.00 | Buy on Amazon |
| 3 |
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OURA Ring 4 Smart Ring - Silver - Size 10 | $349.00 | Buy on Amazon |
| 4 |
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Oura Ring 5 Smart Ring - Silver - Size 10 - Fitness & Sleep Tracker | $399.00 | Buy on Amazon |
| 5 |
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Oura Ring 5 Smart Ring- Gold - Size 8 - Fitness & Sleep Tracker | $399.00 | Buy on Amazon |
These are consumer wellness measurements and interpretations, not diagnoses. Oura Member Care says the ring is “not a medical device and is not intended to diagnose, treat, cure, monitor, or prevent medical conditions or illnesses.” Use appropriate medical equipment and professional advice for health concerns.
How accurate is Oura Ring 4 for sleep?
The evidence in the research reviewed for this article does not establish a universal Ring 4-specific sleep-accuracy percentage. Oura provides sleep measures and scores, but those should not be treated as definitive measurements of brain activity or as a diagnosis. Oura advises users to follow personal trends in its app rather than compare readings directly across different devices, whose sensors, wear locations, and processing differ.
#1 Best Overall
- ACCURACY - SMART SENSING - Oura tracks over 50 health metrics, including sleep, activity, stress, heart health, and women’s health metrics. Oura Ring 4 is powered by Smart Sensing, which adapts to you — delivering accurate, continuous data, day and night
- ACCURATE SIZING ESSENTIAL - Oura Ring 4 uses unique sizing different from standard jewelry rings; use the Oura Ring 4 Sizing Kit to find your perfect fit before purchasing
- LONG LASTING BATTERY - With up to 8 days of battery life, no screens and no vibrations, Oura Ring 4 allows you to focus on the present. From a workout to a night out — you’re free to forget it’s on. Until you start getting compliments
- OURA MEMBERSHIP - First month of membership is included with purchase, for new members only. Subscription is 5.99/mo afterwards. Membership is tied to your account via the Oura App, not your physical ring
- HSA/FSA ELIGIBLE - We can accept HSA or FSA funds for the following: Oura Ring, additional chargers, and shipping
Tom’s Guide reviewer reported that Ring 4 sleep data compared closely with their personal sleep diary during a two-week test. That is one reviewer’s experience, not a controlled validation or a guarantee for every wearer. The practical value is in using repeated readings to notice patterns and changes over time, while remembering that a single score or estimated sleep stage can be imperfect.
Daytime activity and limitations
Ring 4 records movement and activity, but it is not a replacement for a sports watch with a screen, GPS, live workout data, or detailed training tools. Tom’s Guide noted that its step counts could differ from a smartwatch. If precise activity counts or live exercise metrics matter to you, use a dedicated fitness tracker or sports watch rather than relying on the ring alone.
Rank #2
- ACCURACY - SMART SENSING - Oura tracks over 50 health metrics, including sleep, activity, stress, heart health, and women’s health metrics. Oura Ring 4 is powered by Smart Sensing, which adapts to you — delivering accurate, continuous data, day and night
- ACCURATE SIZING ESSENTIAL - Oura Ring 4 uses unique sizing different from standard jewelry rings; use the Oura Ring 4 Sizing Kit to find your perfect fit before purchasing
- LONG LASTING BATTERY - With up to 8 days of battery life, no screens and no vibrations, Oura Ring 4 allows you to focus on the present. From a workout to a night out — you’re free to forget it’s on. Until you start getting compliments
- OURA MEMBERSHIP - First month of membership is included with purchase, for new members only. Subscription is 5.99/mo afterwards. Membership is tied to your account via the Oura App, not your physical ring
- HSA/FSA ELIGIBLE - We can accept HSA or FSA funds for the following: Oura Ring, additional chargers, and shipping
Comfort, sizing, and setup
Ring 4 has a titanium exterior and titanium inner shell. Oura lists it as 7.9 mm wide, approximately 2.88 mm thick, and 3.3–5.2 g depending on size. Comfort is individual, and a snug, comfortable fit is important for sensor contact.
- Use the Ring 4 sizing kit. Oura says sizing differs slightly between generations; do not assume another generation’s sizer will fit the same.
- Wear the sizer for at least 24 hours, including while sleeping. Oura recommends this before choosing a size.
- Orient the sensors toward your palm. Oura recommends placing the sensor side against the palm side of the finger.
- Choose a snug but comfortable fit. Oura recommends the index, middle, or ring finger for signal quality.
Battery life and charging
Oura estimates 5–8 days of battery life per charge and a typical charging time of 20–80 minutes. These are official estimates, not guarantees: Oura says battery life varies with ring size, settings, activity, battery age, and use. In Tom’s Guide’s individual test, the reviewer reported six days from a full charge. That observation should not be taken as a promise of the same result for every owner.
Rank #3
- ACCURACY - SMART SENSING - Oura tracks over 50 health metrics, including sleep, activity, stress, heart health, and women’s health metrics. Oura Ring 4 is powered by Smart Sensing, which adapts to you — delivering accurate, continuous data, day and night
- ACCURATE SIZING ESSENTIAL - Oura Ring 4 uses unique sizing different from standard jewelry rings; use the Oura Ring 4 Sizing Kit to find your perfect fit before purchasing
- LONG LASTING BATTERY - With up to 8 days of battery life, no screens and no vibrations, Oura Ring 4 allows you to focus on the present. From a workout to a night out — you’re free to forget it’s on. Until you start getting compliments
- OURA MEMBERSHIP - First month of membership is included with purchase, for new members only. Subscription is 5.99/mo afterwards. Membership is tied to your account via the Oura App, not your physical ring
- HSA/FSA ELIGIBLE - We can accept HSA or FSA funds for the following: Oura Ring, additional chargers, and shipping
Membership and the subscription catch
Oura Membership unlocks detailed insights and personalized guidance. Without membership, the ring has limited functionality, so the full app experience is not included permanently with the hardware. In the United States, Oura lists membership at $5.99 per month or $69.99 per year before tax, and says new members receive one included month. Pricing varies by region; check Oura’s current product page for local terms.
Tom’s Guide reports that Sleep, Readiness, and Activity scores remain after cancellation, while underlying data and actionable insights are lost. Treat that as the reviewer’s account unless you confirm current cancellation terms with Oura. The recurring fee is worth considering alongside the hardware price: buyers who will use detailed reports and guidance may find the membership valuable, while those seeking only basic readings may not.
Rank #4
- THE WORLD’S SMALLEST SMART RING - 40% smaller than the previous generation, Oura Ring 5 is thinner, lighter and smaller than ever. The updated all-titanium design is more scratch-resistant and comfortable than ever
- SIZING IS ESSENTIAL - Oura Ring 5 uses unique sizing different from standard jewelry rings and other Oura Ring generations; use the Oura Ring 5 Sizing Kit to find your perfect fit before purchasing
- EVERYDAY HEALTH SENSING - Oura tracks over 50 health metrics, including sleep, activity, stress, heart health, metabolic health and women’s health metrics. Oura seamlessly integrates with over 40 apps including Natural Cycles, Strava, & more
- OURA MEMBERSHIP - First month of membership is included with purchase, for new members only. Subscription is 5.99/mo afterwards. Membership is tied to your account via the Oura App, not your physical ring
- REBUILT FOR GREATER ACCURACY - Oura Ring 5 has been re-engineered and reconfigured, providing more precise personal health data. Larger, smarter sensors bring research-grade accuracy—all in Oura’s smallest form factor yet
Who should buy Oura Ring 4?
Consider Ring 4 if you want a discreet wearable for sleep and wellness trends, are comfortable with a subscription, and will use the app’s explanations over time. It is less suitable if you want medical monitoring, dependable step counts, live workout data, GPS, or a full sports-watch experience. Check the current hardware price and membership terms before deciding.
Frequently Asked Questions
Does Oura Ring 4 accurately track sleep?
It provides sleep-related measurements and trends, but the research reviewed here does not establish a universal Ring 4-specific accuracy percentage. Tom’s Guide’s reviewer reported close agreement with their personal sleep diary over two weeks; that is an individual observation, not a guarantee.
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Best Value
- THE WORLD’S SMALLEST SMART RING - 40% smaller than the previous generation, Oura Ring 5 is thinner, lighter and smaller than ever. The updated all-titanium design is more scratch-resistant and comfortable than ever
- SIZING IS ESSENTIAL - Oura Ring 5 uses unique sizing different from standard jewelry rings and other Oura Ring generations; use the Oura Ring 5 Sizing Kit to find your perfect fit before purchasing
- EVERYDAY HEALTH SENSING - Oura tracks over 50 health metrics, including sleep, activity, stress, heart health, metabolic health and women’s health metrics. Oura seamlessly integrates with over 40 apps including Natural Cycles, Strava, & more
- OURA MEMBERSHIP - First month of membership is included with purchase, for new members only. Subscription is 5.99/mo afterwards. Membership is tied to your account via the Oura App, not your physical ring
- REBUILT FOR GREATER ACCURACY - Oura Ring 5 has been re-engineered and reconfigured, providing more precise personal health data. Larger, smarter sensors bring research-grade accuracy—all in Oura’s smallest form factor yet
Can I use Oura Ring 4 without a membership?
Oura says the ring has limited functionality without membership. Membership unlocks detailed insights and personalized guidance. In the US, listed pricing is $5.99 monthly or $69.99 annually before tax, with one included month for new members.
How long does Oura Ring 4 battery last?
Oura estimates 5–8 days per charge and 20–80 minutes for a typical charge. Battery life varies with size, settings, activity, battery age, and use. Tom’s Guide’s reviewer reported six days in their test.
What sizing kit should I use for Oura Ring 4?
Use the Ring 4 sizing kit. Oura recommends wearing a sizer for at least 24 hours, including while sleeping, and placing the sensors against the palm side of the finger.
Is Oura Ring 4 a medical device?
No. Oura Member Care says the ring is not a medical device and is not intended to diagnose, treat, cure, monitor, or prevent medical conditions or illnesses.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
