Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Cross-sectional area according to the needle size
| Needle size (gauge) | Diameter (mm) | Cross-sectional area (mm2) | Cross-sectional area ratio (to 25G) |
|---|---|---|---|
| 21 | 0.819 | 2.106 | 2.53 |
| 22 | 0.718 | 1.619 | 1.94 |
| 23 | 0.642 | 1.294 | 1.55 |
| 24 | 0.566 | 1.006 | 1.21 |
| 25 | 0.515 | 0.833 | 1.00 |
| 26 | 0.464 | 0.676 | 0.81 |
| 27 | 0.413 | 0.536 | 0.64 |
| 28 | 0.362 | 0.411 | 0.49 |
| 29 | 0.337 | 0.357 | 0.43 |
All the values are outer lumen size. Cross-sectional area ratio is calculated in reference to the 25G needle. Underlined values are those used in this report.
