Needle gauge table
Posted by Vincent Rocher on May 20th 2019
Find below the complete table of the inner and outer diameters of hypodermic needle gauges. In microfluidics, needles are mostly used to connect a syringe to a soft-walled tubing. You can use it to determine the needle you should use depending on the inner diameter of your soft-walled tubing.
Example: 23G needle = 0.02525" or 0.6414 mm (outer diameter) - 0.01325" or 0.337 mm (inner diameter).
Tip: always use a needle with a larger outer diameter than the inner diameter of your tubing!
| Needle gauge | Outer diameter (inches) | Outer diameter (mm) | Inner diameter (inches) | Inner diameter (mm) |
| 7 | 0.180 | 4.572 | 0.150 | 3.810 |
|
8 |
0.165 | 4.191 | 0.135 | 3.429 |
| 9 | 0.148 | 3.759 | 0.118 | 2.997 |
| 10 | 0.134 | 3.404 | 0.106 | 2.692 |
| 11 | 0.120 | 3.048 | 0.094 | 2.388 |
| 12 | 0.109 | 2.769 | 0.085 | 2.159 |
| 13 | 0.095 | 2.413 | 0.071 | 1.803 |
| 14 | 0.083 | 2.108 | 0.063 | 1.600 |
| 15 | 0.072 | 1.829 | 0.054 | 1.372 |
| 16 | 0.065 | 1.651 | 0.047 | 1.194 |
| 17 | 0.058 | 1.473 | 0.042 | 1.067 |
| 18 | 0.050 | 1.270 | 0.033 | 0.838 |
| 19 | 0.042 | 1.067 | 0.027 | 0.686 |
| 20 | 0.03575 | 0.9081 | 0.02375 | 0.603 |
| 21 | 0.03225 | 0.8192 | 0.02025 | 0.514 |
| 22 | 0.02825 | 0.7176 | 0.01625 | 0.413 |
| 22s | 0.02825 | 0.7176 | 0.006 | 0.152 |
| 23 | 0.02525 | 0.6414 | 0.01325 | 0.337 |
| 24 | 0.02225 | 0.5652 | 0.01225 | 0.311 |
| 25 | 0.02025 | 0.5144 | 0.01025 | 0.260 |
| 26 | 0.01825 | 0.4636 | 0.01025 | 0.260 |
| 26s | 0.01865 | 0.4737 | 0.005 | 0.127 |
| 27 | 0.01625 | 0.4128 | 0.00825 | 0.210 |
| 28 | 0.01425 | 0.3620 | 0.00725 | 0.184 |
| 29 | 0.01325 | 0.3366 | 0.00725 | 0.184 |
| 30 | 0.01225 | 0.3112 | 0.00625 | 0.159 |
| 31 | 0.01025 | 0.2604 | 0.00525 | 0.133 |
| 32 | 0.00925 | 0.2350 | 0.00425 | 0.108 |
| 33 | 0.00825 | 0.2096 | 0.00425 | 0.108 |
| 34 | 0.00725 | 0.1842 | 0.00325 | 0.0826 |
