>>11356393
I usually hear you generally go a bit smaller than your flaccid size. flaccid dick is quite squishy anyways so accidentally picking a "too small" size isnt often an issue.
I'm around 9 to 10cm flaccid, and a 7.9 cm long cage is a comfy fit, sometimes I even wish I went smaller as I personally enjoy the idea of a tight squish.
as the faq in the op says, ring size is the more important measurement, which btw read that faq if you havent already