Millimeters to French
Type a value in mm to get it in Fr instantly.
42Fr
That's 1.08× as wide as a colonoscope — nothing on our list beats it. Its circumference is about 43.98 mm.
Convert the other way: Fr to mm
What it means
How wide is that tube?
French gives the outer diameter. The inner lumen is smaller and depends on the wall thickness and material.
The math
How to convert mm to Fr
To convert millimeters to French, multiply by 3.
Example: 14 mm × 3 = 42 Fr.
In the other direction, 1 Fr = 0.333333 mm.
Every unit
That tube size in every unit
Tables
mm to Fr conversion table
| mm | Fr |
|---|---|
| 3 mm | 9 Fr |
| 4 mm | 12 Fr |
| 5 mm | 15 Fr |
| 6 mm | 18 Fr |
| 7 mm | 21 Fr |
| 8 mm | 24 Fr |
| 10 mm | 30 Fr |
| 12 mm | 36 Fr |
| 14 mm | 42 Fr |
| 16 mm | 48 Fr |
| 18 mm | 54 Fr |
| 20 mm | 60 Fr |
| 22 mm | 66 Fr |
| 24 mm | 72 Fr |
| 28 mm | 84 Fr |
| 30 mm | 90 Fr |
Fr to mm conversion table
| Fr | mm |
|---|---|
| 3 Fr | 1 mm |
| 4 Fr | 1.33333 mm |
| 5 Fr | 1.66667 mm |
| 6 Fr | 2 mm |
| 7 Fr | 2.33333 mm |
| 8 Fr | 2.66667 mm |
| 10 Fr | 3.33333 mm |
| 12 Fr | 4 mm |
| 14 Fr | 4.66667 mm |
| 16 Fr | 5.33333 mm |
| 18 Fr | 6 mm |
| 20 Fr | 6.66667 mm |
| 22 Fr | 7.33333 mm |
| 24 Fr | 8 mm |
| 28 Fr | 9.33333 mm |
| 30 Fr | 10 mm |
Quick answers
Quick answers
- How many Fr is 1 mm?
- 1 mm is 3 Fr.
- How many Fr is 10 mm?
- 10 mm is 30 Fr.
- How many Fr is 14 mm?
- 14 mm is 42 Fr.
The units
About these units
Millimeters (mm)
Outer diameter in millimeters.
French (Fr)
Outer diameter in thirds of a millimeter.
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