Oura launches Ring 5, the world’s smallest smart ring

Finnish health‑tech company Oura announced the Oura Ring 5, its latest generation of smart rings. The device is 40 % smaller than the Ring 4, measuring 6.09 mm wide and 2.28 mm thick, and weighs between 2 g and 2.69 g, making it the smallest smart ring on the market. Its design resembles ordinary jewelry, aiming to be indistinguishable from a regular ring.

The Ring 5 is priced at $399 and focuses on continuous sleep and health monitoring. Battery life has been extended to 6–9 days per charge, compared with 5–8 days on the previous model. Oura cites improved comfort during overnight wear and more accurate sleep data as key benefits. The launch comes as Oura faces competition from lighter, lower‑cost smart‑ring rivals such as RingConn and Ultrahuman.

The new ring is expected to appeal to users who want discreet, wearable health tracking without the bulk of a smartwatch.