Oura Ring Gen 3 Sizing Kit

Oura Ring integrates advanced technology with a deep understanding of wellness, offering a truly holistic approach to health tracking. Backed by an in-house team of over 20 PhDs, the rings were refined across four generations, each version smarter, lighter, and more durable than the last, trusted by millions of users worldwide. Its research-grade sensors, comparable to those used in sleep labs, provide highly accurate to ensure you get reliable insights for your wellbeing.

The ring also continuously fine-tunes your health data, delivering increasingly personalised feedback the longer it’s worn. Additionally, each Oura Ring is made from aerospace-grade titanium, one of the strongest materials on earth. Years of testing guarantee they're comfortable to wear and will last long– making them a reliable partner that powers your lifelong health journey.

Born in the happiest country in the world, Oura is the wellness brand behind the revolutionary Oura Ring and Oura App. Combining Finnish craftsmanship with cutting-edge technology, its mission is simple: to make health a daily practice. That’s why they created a tool that fits seamlessly into daily life, offering clear insights to support wellbeing. Empowering individuals to take control of their health, Oura guides everyone on their journey, helping them make informed decisions and lead better, healthier lives.

With our Healf Curation Process, we do the work for you. Shop with confidence knowing that every item has been tried, tested, and curated for you.

Learn more about each step—Brand Discovery, Expert Validation, and Community Testing—here.

Shipping

At Healf, we prioritize safe and fast delivery for all our customers. Our carefully selected couriers are Royal Mail and DPD.

UK standard delivery

Enjoy free standard delivery on orders above £50, this option usually requires 2-3 working days. If your order is under £50, this delivery option is available for £3.99.

Next working day

For when you need our products urgently, we offer next working day shipping for £5.99. For orders placed before 12.00, we will ship it the same day to ensure you receive your order the next working day.

International

International deliveries can take 7 working days, and up to 4 weeks. The cost is £22.99 for orders below £50, £49.95 for orders above.

Returns

If for any reason you are not satisfied with your order, we provide free 365-day UK returns for all our customers. To initiate your return, simply contact us at team@healf.com, and we'll send you a return slip and help arrange a collection. The item you return must be sent in the same condition as received and inside the original packaging. Once received, we will notify you via email.

For international returns, we unfortunately do not cover the cost. However, we work with an array of carriers and can offer self-posting returns for customers shopping from outside the UK.

HOW TO CHOOSE THE RIGHT SIZE

Ring Sizers as Guidelines
The ring sizers provided are intended as guidelines for selecting the correct size. They do not reflect the exact feel and quality of the Oura Ring that will be received once an order is updated.

Open the Sizing Kit
Inside the sizing kit, plastic ring sizers are included (sizes 4–15 for Oura Ring 4, sizes 6–13 for Gen3). Oura Ring sizes differ slightly from standard US ring sizes, and half sizes are not offered.

The Oura Ring and ring sizers have the same width and circumference, though the Oura Ring is slightly heavier due to differences in materials.

Choose the Finger
The Oura Ring can be worn on any finger and on either hand. For the best performance and accuracy, it is recommended to wear the Oura Ring on the index finger.

If the index finger is not preferred, the middle or ring fingers are the next best options. It’s important to avoid fingers with large knuckles, as the base of the finger may be narrower than the knuckle.

Trying the ring on different fingers can help determine the ideal fit. The ring can be moved between fingers and hands if necessary due to changes in finger size.

Confirm the Ring Orientation
For the Oura Ring 4, wear the ring sizer with the size number visible on the top of the hand.

For the Oura Ring Gen3, ensure the sensor bumps inside the ring sizer are placed on the palm side of the finger (the pad).

Ensure a Comfortable Fit
The Oura Ring should fit snugly around the base of the finger, ensuring it is secure without feeling too tight during regular wear. The right size will be comfortable for extended periods and will not easily slide off, but it should come off with a bit of soap and water.

Test the Snugness
Test the fit by making a fist while wearing the ring sizer. If there is a gap between the top of the finger and the inside of the ring, a smaller size may be needed.

Wear for 24 Hours
Finger size can fluctuate based on environmental factors, so it is advised to wear the ring sizer for at least 24 hours to ensure the best fit. The ring should not rotate as daily tasks are performed.

Confirm the Ring Size
Once the ideal size is chosen:
If the sizing kit was purchased from the Oura online store, sign in to My Account and confirm the ring size. An email will be sent once the order has been dispatched.

If the sizing kit was purchased from an authorised retailer, return to the retailer to purchase the correct ring size.