Just like measuring the penis, there is method to measure foreskin and how much you have. Natural (uncut) foreskins vary considerably between one man and another. Some uncut men have very little foreskin and may appear to be circumcised, others have a very long foreskin.
With the Coverage Index you can quantify how much foreskin you have no matter whether you’re circumcised or natural.
The Coverage Index is based on the amount of foreskin coverage a penis has. It ranges from virtually none (predominantly men who have been heavily circumcised) through to very long (predominantly uncut penises with very long foreskins). It has been designed so every man on earth can use this index to determine his CI number.
Because many circumcised penises appear to have the same amount of foreskin when erect (i.e. none) and many uncut penises appear to have the same amount of foreskin when soft (i.e. a large amount) it was necessary to develop an index that takes foreskin coverage in both the erect and soft states into account. When determining your CI number consider the amount of foreskin you normally have when soft and normally have when erect.