Is the Oura Ring 4 worth it over the Ring 3?

Yes for most buyers: the 4 has better sensor accuracy, a slimmer fit and longer battery life. The 3 is only worth considering if you find it at a much lower value and do not mind older sensors.

Do I need a subscription to use it?

You can see basic scores without one, but detailed sleep, readiness and long-term insights need the Oura membership. Budget for that recurring cost.

How long does the battery last?

Oura rates it at up to 8 days, and most owners get close to that with normal use. Heavy SpO2 or workout use shortens it.

Can I swim and shower with it?

Yes. It is rated 10 ATM, so pools, showers and shallow swimming are fine. Avoid high-pressure water and deep diving.

Does it track GPS or workouts on its own?

No. The ring has no GPS and relies on your phone for route data. It logs activity and heart rate but is not a full sports watch.

How do I pick the right size?

Use the Oura sizing kit and wear the sample ring for a full day, including overnight. The index, middle or ring finger on your non-dominant hand usually fits best.