To find the size of your curved barbell you need to measure the inner length between the two balls (or jewels) in a straight line. As previously indicated, the barbell length will be between 6mm(1/4inch) to 12mm(1/2inch). 10mm(3/8inch) remains the most common barbell length for a belly button piercing.
Keeping this in view, is 30 too old for a belly ring?
“If you think you’re too old then you’re too old.” Some people definitely agree that a belly ring over 25 is trashy/tragic whilst others think that it’s fine but over 30 is cause for concern.