Oura Ring 5 vs Ring 4 sizing

The short version: do not assume your Ring 4 size is your Ring 5 size. Oura lists Ring 5 in sizes 6-13 and says its sizing is slightly different from Ring 4, which runs 4-15.

ModelSize rangeCarry-over guidance
Oura Ring 5 6-13 Use the Ring 5 sizing kit before ordering.
Oura Ring 4 4-15 Ring 4 kit results are a reference, not a final Ring 5 order size.

Smart-ring advisor

Smart-ring sizing advisor

If you already know your Ring 4 size

Use it only to narrow what you test first. If the old size is 4, 5, 14 or 15, it is outside the Ring 5 range. If it is 6-13, start near that number but confirm with the Ring 5 sizing kit before locking the order.

Smart-ring sizing is about sensor contact, not just circumference. Wear the sample through normal daily swelling and sleep when the brand recommends it.

Frequently asked questions

Does my Oura Ring 4 size carry over to Oura Ring 5?

Not safely. Oura says Ring 5 sizing is slightly different from Ring 4, so use the Ring 5 sizing kit instead of auto-ordering the same number.

What sizes does Oura Ring 5 come in?

Oura Ring 5 is listed in whole sizes 6 through 13.

What sizes does Oura Ring 4 come in?

Oura Ring 4 sizing runs from whole size 4 through 15.