Gauge to French
Type a value in G to get it in Fr instantly.
2.154Fr
That's 1.39× as thick as a 25 G vaccination needle, while a 21 G blood-test needle is 1.14× thicker. That is about 10.26 times the thickness of a human hair.
Convert the other way: Fr to G
What it means
How thick is that needle?
Nominal outer diameters from the ISO 9626 table. Thin-wall and regular-wall needles of the same gauge share the outside diameter but differ inside.
The math
How to convert G to Fr
Gauge is a table, not a formula: 21 G = 0.819 mm, 23 G = 0.642 mm, and values between gauges are interpolated.
Example: 22 G = 2.154 Fr.
Every unit
That needle in every unit
Tables
G to Fr conversion table
| G | Fr |
|---|---|
| 14 G | 6.324 Fr |
| 16 G | 4.953 Fr |
| 18 G | 3.81 Fr |
| 19 G | 3.201 Fr |
| 20 G | 2.724 Fr |
| 21 G | 2.457 Fr |
| 22 G | 2.154 Fr |
| 23 G | 1.926 Fr |
| 24 G | 1.698 Fr |
| 25 G | 1.545 Fr |
| 26 G | 1.392 Fr |
| 27 G | 1.239 Fr |
| 28 G | 1.086 Fr |
| 29 G | 1.011 Fr |
| 30 G | 0.936 Fr |
| 31 G | 0.783 Fr |
| 32 G | 0.705 Fr |
Fr to G conversion table
| Fr | G |
|---|---|
| 0.705 Fr | 32 G |
| 0.783 Fr | 31 G |
| 0.936 Fr | 30 G |
| 1.01 Fr | 29.0133 G |
| 1.09 Fr | 27.9739 G |
| 1.24 Fr | 26.9935 G |
| 1.39 Fr | 26.0131 G |
| 1.55 Fr | 24.9673 G |
| 1.7 Fr | 23.9912 G |
| 1.93 Fr | 22.9825 G |
| 2.15 Fr | 22.0175 G |
| 2.46 Fr | 20.9888 G |
| 2.72 Fr | 20.015 G |
| 3.2 Fr | 19.0021 G |
| 3.81 Fr | 18 G |
| 4.95 Fr | 16.0056 G |
| 6.32 Fr | 14.0048 G |
Quick answers
Quick answers
- How many Fr is 10 G?
- 10 G is 10.212 Fr.
- How many Fr is 22 G?
- 22 G is 2.154 Fr.
The units
About these units
Gauge (G)
The Birmingham/Stubs number printed on the hub.
French (Fr)
The catheter scale: thirds of a millimeter.
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