Oura Ring 4 Black Size 5 - Smart Ring for Sleep and Health

Our review of the Oura Ring 4 shows it is best for people who want a discreet, 24/7 health tracker focused on sleep and recovery; the single biggest reason to buy is its combination of accurate sleep tracking and up to eight days of battery life in a subtle, all-titanium form. The ring is designed to be worn constantly, with Smart Sensing that adapts to the wearer and delivers continuous insights across sleep, readiness, activity and heart health. Size carefully with the Oura Sizing Kit before purchasing since Oura uses unique sizing rather than standard US ring sizes.

Key Features

• Unique Sizing: Oura Ring 4 uses its own sizing system so the included Sizing Kit helps you get the best fit and most reliable biometric readings.
• Smart Sensing Accuracy: The ring tracks more than 50 health metrics and adapts to you, improving continuous monitoring of sleep, heart rate and stress.
• Long Battery Life: With up to eight days between charges, the ring stays on through workouts, sleep and daily life without frequent charging interruptions.
• All-Titanium Design: A durable, lightweight titanium body is water resistant and intended for comfortable 24/7 wear, even for sensitive skin.
• App Ecosystem: Seamless syncing with iOS and Android and integrations with over 40 apps, including Apple Health and Strava, make it simple to consolidate health data.
• Membership Included: First month of Oura membership is included for new members, with ongoing subscription options if you want advanced insights and history.

Who It's For

The Oura Ring 4 is ideal for people who prioritize sleep and recovery metrics and prefer a discreet wearable instead of a wrist device; athletes, biohackers and anyone tracking long-term trends will appreciate the continuous heart rate and sleep staging data. It is also a good option for those who value a minimalist, durable design and multi-day battery life.

It is less suitable for someone who needs vibration alerts, a display, or standard US ring sizing-buyers must size with the Sizing Kit first. If you rely heavily on tactile notifications or expect a smartwatch replacement for on-wrist interactions, a different wearable may be a better fit.

Pros & Cons

Pros

• Strong sleep tracking and broad health metrics with adaptive Smart Sensing.
• Comfortable, water resistant all-titanium design made for constant wear.
• Long battery life reduces friction in day to day use.
• Good app integrations and initial membership included for new users.

Cons

• Requires correct sizing via the Sizing Kit since sizes differ from standard US ring sizes.
• Some customers report mixed experiences with battery life and functionality, so real-world longevity varies.

Specifications

Our Verdict

The Oura Ring 4 is a strong choice for anyone who wants a discreet, comfortable health tracker with excellent sleep tracking and multi-day battery life. It delivers valuable continuous insights in a durable package, but buyers must size carefully and be aware that battery and functionality experiences can vary.

Frequently Asked Questions

Do I need a membership to use the ring?
The first month of membership is included for new members; ongoing access to advanced historical insights requires a paid subscription.

How do I ensure the ring fits correctly?
Size yourself using the Oura Ring 4 Sizing Kit before buying because Oura uses its own sizing system rather than standard US ring sizes.

Can I wear the ring while exercising and sleeping?
Yes. The ring is designed for 24/7 wear, is water resistant, and tracks activity, heart health and sleep continuously.