When choosing your Oura ring size, we recommend taking time to test different sizes and different fingers. Finding the perfect fit ensures you get the benefits of uninterrupted long-term data.

Here are some tips to help you find your perfect Oura ring size for you.

Take your time

Taking the time to find the right Oura ring size is worth it. You'll get better results and wear it for longer when the size is right. If possible, wear a sizing ring for 24 hours or do the sizing at different times of the day. 

Make sure your hands are warm

The size of your fingers changes throughout the day. If your hands are cold when trying on the ring, your fingers could be smaller than usual. Walk around the block, take the stairs or do some jumping jacks to get the blood flowing.

If you have large knuckles and thin fingers, take extra care to find a size that slips over your knuckles but isn't too loose around the base of your finger.

Make sure the ring is positioned correctly

See the tiny bumps inside the sizing ring? These are the LEDs that measure your Blood Pulse Volume from the arteries on your finger. To ensure the best possible measurement accuracy, make sure that the LEDs are on the palm side of your finger, in contact with your skin.

Which finger should I wear the Oura ring on?

  • Any finger (including pinky and thumb), on either hand. In terms of signal quality, the index, middle and ring finger usually work best.
  • If possible, choose a size you can wear on more than one finger. It's ok to switch the ring to a different finger if needed.
  • If possible, don't wear the Oura ring next to other rings (on the same finger or adjacent fingers).

Your ring is just right when

  • it's comfortable to wear, for extended periods of time
  • it doesn't feel too tight in the morning
  • the sensor bumps inside the band are in contact with your skin on the palm side of your finger

Your ring is too tight when 

  • it feels uncomfortable 
  • you can't get it off without twisting it or using water/lotion
  • if the ring doesn't turn at all on your finger even if you twist it

Your ring is too loose when

  • it falls off when you relax your fingers
  • it turns freely on your finger
  • the sensor bumps don't rest against your skin

In between sizes? 

The Oura ring comes in full sizes US6-US13. Currently half-sizes are not available.

If you're in between sizes, it's usually better to choose the more comfortable size or try a different finger. The ring should still be tight enough so that the LED bumps are in contact with your skin. This is especially important during the night, when heart rate tracking is enabled. If you have large knuckles, go for smallest size you can get over your knuckle. A little bit of effort may be needed, but don't push it - removing the ring on a daily basis shouldn't feel too painful. If the ring is too tight, use water or lotion when removing the ring to protect your finger. If using water, remember to dry your hands before putting the ring back on.

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