What is the appropriate age to gauge your ears?

17 years. You need to consider what you want to do in life before you go messing up your ears for the public to see. Most employers and some schools will require you take out the piercings when you are on the floor in public view, so you need to think about this BEFORE you go doing something that may be an issue down the road. Research the idea and know how to do it right the first time without damaging the tissue to the point of an expensive surgical repair.