Oura Ring Size Chart
Oura Ring sizing figures, US 6-13, with UK/Australia equivalents and internal diameter.
Oura Ring sizes (US 6-13)
Oura ships its own sizing kit before your ring order — use this table for a rough estimate only.
| US Size | UK / Australia | Internal Diameter (mm) | Circumference (mm) | Approx. (cm) |
|---|---|---|---|---|
| US Size6 | UK / AustraliaL 1/2 | Internal Diameter (mm)16.45 | Circumference (mm)51.6 | Approx. (cm)5.16 cm |
| US Size7 | UK / AustraliaN 1/2 | Internal Diameter (mm)17.3 | Circumference (mm)54.4 | Approx. (cm)5.44 cm |
| US Size8 | UK / AustraliaP 1/2 | Internal Diameter (mm)18.2 | Circumference (mm)57.2 | Approx. (cm)5.72 cm |
| US Size9 | UK / AustraliaR 1/2 | Internal Diameter (mm)19 | Circumference (mm)59.7 | Approx. (cm)5.97 cm |
| US Size10 | UK / AustraliaT 1/2 | Internal Diameter (mm)19.8 | Circumference (mm)62.3 | Approx. (cm)6.23 cm |
| US Size11 | UK / AustraliaV 1/2 | Internal Diameter (mm)20.6 | Circumference (mm)64.9 | Approx. (cm)6.49 cm |
| US Size12 | UK / AustraliaX 1/2 | Internal Diameter (mm)21.4 | Circumference (mm)67.5 | Approx. (cm)6.75 cm |
| US Size13 | UK / AustraliaZ+1 | Internal Diameter (mm)22.2 | Circumference (mm)70.1 | Approx. (cm)7.01 cm |
Oura Ring sizing works differently from a regular ring
Oura Rings are worn snugly for its health sensors to maintain skin contact, so its sizing can run differently from a ring you'd wear loosely for jewelry. Oura provides a free sizing kit before shipping your actual ring — use that kit to confirm your size rather than relying on this table or your regular ring size alone.
For a fit checked against our own verified conversion data, try the ring size calculator.
Frequently asked questions
Is this the official Oura Ring sizing chart?
No — these figures are reproduced from a third-party source, not sourced or verified directly from the manufacturer or an official standards body. Always confirm with the manufacturer or retailer before purchasing.
Why isn't this data verified like the rest of your site?
Every other page here traces its sizing figures back to one dataset we maintain and test ourselves. This page instead mirrors numbers published by a third party, at face value, so you can compare it alongside our own verified US/UK/EU/Germany/Japan chart and calculator.