Catheter French Sizes 101

Choosing the right catheter French size is crucial for comfort and effective drainage. But what do French sizes actually mean? If you’ve ever looked at catheter packaging and seen numbers like 12 Fr or 16 Fr, you might be wondering how these sizes are determined and why they matter.

Understanding catheter French sizes can help you find the best fit for your needs, reducing discomfort and ensuring proper urine flow. 

Urinary Catheter French Sizes and Types

French Sizing

Catheter sizes range anywhere from pediatric to adult men and women. Your doctor will ultimately determine the right catheter size for you. Urinary catheter size is determined by the external diameter of the tube. The universal gauge used for determining this number is known as the French size (FR size) The higher the number, the larger the diameter. To determine the size of a urinary catheter, simply multiply the diameter length in millimeters by 3. For example, if the catheter has a diameter of 4.7 mm, it will have a French size of 14 (14 FR).

Most catheters with funnels utilize a universal coding system to determine their size. Use it for reference when determining your French size.

Catheter Length

Catheter length is determined by body type, with factors of age, weight, and sex considered. A shorter catheter length is always recommended for optimal efficiency and speed of the process. If a patient is heavier or has a larger build, a longer catheter tube will most likely be recommended. Men also need a much longer catheter tube than women. The typical catheter lengths are as follows:

• Pediatric: 10”
• Female: 6-8”
• Male/Unisex: 16”

Why is the right French catheter size important?

Correct catheter sizing is critical to the self-catheterization process for a number of reasons:

1. If the French size (FR) is too small, emptying the bladder will take a considerable amount of time. 
2. If the catheter's French size is too big for the urethra, there may be pain during catheter insertion.
3. A catheter size that is too large may result in mucosal irritation and localized trauma.
4. A catheter size that is smaller than the urethra will result in leakage. 

Choosing the proper catheter size is important for your comfort level and efficiency during self-catheterization.

Patient Care Medical wants your catheter experience to be as smooth and painless as possible.

 To inquire about our selection of catheters, contact us today to speak with one of our specialists.