Body jewelry can be measured in both inches and millimeters. The charts below show the various gauges and lengths in both inches and millimeters.
| Gauge | Inches | Millimeters |
| 0000 | .460 | 11.684 |
| 000 | .410 | 10.404 |
| 00 | .365 | 9.266 |
| 0 | .325 | 8.26 |
| 2 | .257 | 6.54 |
| 4 | .204 | 5.19 |
| 6 | .162 | 4.12 |
| 8 | .128 | 3.26 |
| 10 | .102 | 2.59 |
| 12 | .081 | 2.05 |
| 14 | .064 | 1.63 |
| 16 | .051 | 1.29 |
| 18 | .040 | 1.02 |
| 20 | .032 | .812 |
| Inches | Decimal inches | Millimeters |
| 1/8" (shortest) | .125 | 3.2 |
| 3/16" | .1875 | 4.8 |
| 1/4" | .250 | 6.4 |
| 5/16" | .3125 | 7.94 |
| 3/8" | .375 | 9.5 |
| 7/16" | .4375 | 11.11 |
| 1/2" | .500 | 12.7 |
| 9/16" | .5625 | 14.29 |
| 5/8" | .625 | 15.9 |
| 11/16" | .6875 | 17.46 |
| 3/4" | .750 | 19.0 |
| 13/16" | .8125 | 20.64 |
| 7/8" | .875 | 22.2 |
| 15/16" | .9375 | 23.81 |
| 1" | 1.000 | 25.4 |
| 1-1/4" | 1.25 | 31.75 |
| 1-5/16" | 1.3125 | 33.34 |
| 1-3/8" | 1.375 | 34.93 |
| 1-7/16" | 1.4375 | 36.51 |
| 1-1/2" | 1.5 | 38.1 |
| 1-9/16" | 1.5625 | 39.69 |
| 1-5/8" | 1.625 | 41.28 |
| 1-11/16" | 1.6875 | 42.86 |
| 1-3/4" | 1.75 | 44.45 |
| 1-13/16" | 1.8125 | 46.04 |
| 1-7/8" | 1.875 | 47.63 |
| 1-15/16" | 1.9375 | 49.21 |
| 2" (longest) | 2 | 50.8 |
