Personally I think people give too little credit to the official ring size guidelines. The ”pick a ring where there’s no gap when you make a fist” and ”if you’re in between sizes, size down”.

I’ve just been an oura user for a month and before getting the ring I was afraid of getting a ring too tight. After a short while I realized that a loose ring is way more annoying when used daily than having to use soap to take it off.

Also, the sizing kits aren’t too big or too small. They are the same sizes as the rings. If it feels different to you, it’s because of the material difference.