When it comes to the piercings some think, they can get any size jewelry if it "looks" close. You can not, so this is where measurements come in. You have to know what gauge and size of jewelry you need to purchase so that it will fit the piercing you have.
When you buy Straight Barbells, you must remember the length is the distance between the balls not with the balls. With tongue rings, they are usually 14 gauges with a 3/4 inch barbell to start. Then when it is healed, they usually put in a 5/8 inch. You want a longer one in to begin with because your tongue swells when first done.
When getting your navel or belly button done you usually have a 14 gauge and 7/16 Captive Ring put in. After the healing period, you may want to go with the 3/8 inch even though many people stay with the 7/16. When you are talking about Any Type of Ring, or even Circular Barbells they are listed as gauge with the diameter in inches for the size. The diameter is INSIDE diameter not the overall size of the ring.
The Curved Barbell is the most popular piece and the length of it is measured in a straight line between the 2 balls, not counting the balls in the measurement. You don’t follow the curve when measuring.
Many times you will have pieces listed in Millimeters instead of inches, so here is a conversion chart for you, so you will understand what each means and the conversion, as well as the sizing charts with pictures to show you exactly how to measure your piece which you can find here; Sizing Chart
If you have questions regarding the proper size for any of your piercings it would be in your best interest to talk email us or talk with another expert.