• Choosing a Finger - The Oura Ring 4 can be worn on any finger. Please be sure to measure the finger size on which you plan to wear the Oura Ring. For best performance and accuracy, we recommend wearing the Oura Ring on your index, middle, or ring finger.

Find your right size - The Oura Ring 4 should fit comfortably at the base of your finger, but not so tight as to cause discomfort. When taking your size, the ring must be able to cover the widest part of your finger, such as the knuckle.

• Size - Oura Ring 4 is available in sizes 4 to 15; we do not currently offer half sizes. Oura Ring sizes differ slightly from standard ring sizes, so you should not assume your known ring size directly.

Materials - Our size measuring rings are made of plastic, while the Ora Ring 4 body is crafted entirely from titanium to ensure comfort. Because the size measuring rings are made using plastic molds, they may feel less comfortable than the actual Ora Ring you eventually receive.

*Size measurement kits are considered consumables and are non-refundable and non-returnable.