Millimeters to Charrière
Type a value in mm to get it in Ch instantly.
42Ch
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: Ch 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 Ch
To convert millimeters to Charrière, multiply by 3.
Example: 14 mm × 3 = 42 Ch.
In the other direction, 1 Ch = 0.333333 mm.
Every unit
That tube size in every unit
Tables
mm to Ch conversion table
| mm | Ch |
|---|---|
| 3 mm | 9 Ch |
| 4 mm | 12 Ch |
| 5 mm | 15 Ch |
| 6 mm | 18 Ch |
| 7 mm | 21 Ch |
| 8 mm | 24 Ch |
| 10 mm | 30 Ch |
| 12 mm | 36 Ch |
| 14 mm | 42 Ch |
| 16 mm | 48 Ch |
| 18 mm | 54 Ch |
| 20 mm | 60 Ch |
| 22 mm | 66 Ch |
| 24 mm | 72 Ch |
| 28 mm | 84 Ch |
| 30 mm | 90 Ch |
Ch to mm conversion table
| Ch | mm |
|---|---|
| 3 Ch | 1 mm |
| 4 Ch | 1.33333 mm |
| 5 Ch | 1.66667 mm |
| 6 Ch | 2 mm |
| 7 Ch | 2.33333 mm |
| 8 Ch | 2.66667 mm |
| 10 Ch | 3.33333 mm |
| 12 Ch | 4 mm |
| 14 Ch | 4.66667 mm |
| 16 Ch | 5.33333 mm |
| 18 Ch | 6 mm |
| 20 Ch | 6.66667 mm |
| 22 Ch | 7.33333 mm |
| 24 Ch | 8 mm |
| 28 Ch | 9.33333 mm |
| 30 Ch | 10 mm |
Quick answers
Quick answers
- How many Ch is 1 mm?
- 1 mm is 3 Ch.
- How many Ch is 10 mm?
- 10 mm is 30 Ch.
- How many Ch is 14 mm?
- 14 mm is 42 Ch.
The units
About these units
Millimeters (mm)
Outer diameter in millimeters.
Charrière (Ch)
The same scale under its inventor’s name, used across Europe.
Keep going