Oura Ring 4 sizing guide

Oura uses whole-number sizes that are close to US labels, but the final fit is brand-specific. Do not order from a jewelry size alone — use the Oura Ring 4 sizing kit and wear the sample for at least 24 hours, including sleep.

Sizing system	Proprietary whole numbers (US-style, no half sizes)
Size range	Sizes 4–15
Sizing kit	Use the Oura Ring 4 sizing kit; Size Later includes a complimentary kit, and many retailers sell kits with purchase credit.
Price	Check Oura

Smart-ring advisor

Check smart-ring fit

My usual jewelry size Target smart ring Old Oura Ring 4 size, optional

Does my normal ring size fit?

Use the ring size converter to find your standard size first — it's a useful starting point — but always confirm the Oura Ring 4 fit with the brand's sizing kit or sizing flow.

Frequently asked questions

Is my Oura ring size the same as my normal ring size?

Treat your normal ring size as a starting point only. Oura says its sizes differ slightly from standard ring sizes and recommends the generation-specific sizing kit before ordering.

What sizes does the Oura Ring 4 come in?

Oura Ring 4 is listed in whole sizes 4 through 15, with no half sizes.

Compare all devices on the smart ring sizing guide.