Oura Ring Size Guide: Standard Ring Size vs Oura Sizing
How Oura Ring sizing differs from standard jewellery sizes, which sizing kit to use, and how to test the fit before ordering.
Oura Ring 4: 4–15; Oura Ring 5: 6–13
Important differenceOura uses whole sizes, but its sizes differ slightly from standard US jewellery sizes and also differ between product generations.
Our sizing recommendation
Use the sizing kit made for your exact Oura generation, then test the chosen size before confirming your order. Do not convert your ordinary ring size directly.
Smart rings contain sensors and have a different inner profile from conventional jewellery. A calibrated jewellery measurement can provide a starting point, but the manufacturer’s own sizing kit is the final authority.
Use the correct Oura Ring sizing kit.
Check the generation before ordering: smart-ring sizing kits are not universally interchangeable.
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Fact checked against Official Oura sizing guidance. Brand names belong to their respective owners. RingSize.app is independent and is not endorsed by the manufacturer.